diff --git a/src/main/java/org/codelibs/fess/app/service/SearchLogService.java b/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
index 50086577e..7fe47ea3b 100644
--- a/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
+++ b/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
@@ -544,6 +544,9 @@ public class SearchLogService {
             e.getSearchFieldLogList().stream().forEach(p -> {
                 params.put(p.getFirst(), p.getSecond());
             });
+            e.getRequestHeaderList().stream().forEach(p -> {
+                params.put(p.getFirst(), p.getSecond());
+            });
             return params;
         }).get();
     }
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java b/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
index d6c35a915..e69dd6b56 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
@@ -451,7 +451,10 @@ public class AdminBackupAction extends FessAdminAction {
                 appendJson("requested-at", entity.getRequestedAt(), buf).append(',');
                 final Map<String, List<String>> searchFieldMap = entity.getSearchFieldLogList().stream()
                         .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
-                appendJson("search-field", searchFieldMap, buf);
+                appendJson("search-field", searchFieldMap, buf).append(',');
+                final Map<String, List<String>> requestHeaderMap = entity.getRequestHeaderList().stream()
+                        .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
+                appendJson("headers", requestHeaderMap, buf);
                 buf.append('}');
                 buf.append('\n');
                 try {
diff --git a/src/main/java/org/codelibs/fess/es/log/exbhv/SearchLogBhv.java b/src/main/java/org/codelibs/fess/es/log/exbhv/SearchLogBhv.java
index 6467b22f5..74f0c9693 100644
--- a/src/main/java/org/codelibs/fess/es/log/exbhv/SearchLogBhv.java
+++ b/src/main/java/org/codelibs/fess/es/log/exbhv/SearchLogBhv.java
@@ -86,6 +86,24 @@ public class SearchLogBhv extends BsSearchLogBhv {
                     }
                 });
             }
+            final Object headersObj = source.get("headers");
+            if (headersObj instanceof Map) {
+                ((Map<String, ?>) headersObj).entrySet().stream().forEach(e -> {
+                    if (e.getValue() instanceof String[]) {
+                        final String[] values = (String[]) e.getValue();
+                        for (final String v : values) {
+                            result.getRequestHeaderList().add(new Pair<>(e.getKey(), v));
+                        }
+                    } else if (e.getValue() instanceof List) {
+                        final List<String> values = (List<String>) e.getValue();
+                        for (final String v : values) {
+                            result.getRequestHeaderList().add(new Pair<>(e.getKey(), v));
+                        }
+                    } else if (e.getValue() != null) {
+                        result.getRequestHeaderList().add(new Pair<>(e.getKey(), e.getValue().toString()));
+                    }
+                });
+            }
             return result;
         } catch (final Exception e) {
             final String msg = "Cannot create a new instance: " + entityType.getName();
diff --git a/src/main/java/org/codelibs/fess/es/log/exentity/SearchLog.java b/src/main/java/org/codelibs/fess/es/log/exentity/SearchLog.java
index fc507aee2..913bf9638 100644
--- a/src/main/java/org/codelibs/fess/es/log/exentity/SearchLog.java
+++ b/src/main/java/org/codelibs/fess/es/log/exentity/SearchLog.java
@@ -43,6 +43,8 @@ public class SearchLog extends BsSearchLog implements SearchLogEvent {
 
     private final List<Pair<String, String>> searchFieldLogList = new ArrayList<>();
 
+    private final List<Pair<String, String>> headerList = new ArrayList<>();
+
     private OptionalEntity<UserInfo> userInfo;
 
     private Map<String, Object> fields;
@@ -73,6 +75,12 @@ public class SearchLog extends BsSearchLog implements SearchLogEvent {
         }
     }
 
+    public void addRequestHeaderValue(final String name, final String value) {
+        if (StringUtil.isNotBlank(name) && StringUtil.isNotBlank(value)) {
+            headerList.add(new Pair<>(name, value));
+        }
+    }
+
     public void addDocument(final Map<String, Object> doc) {
         documentList.add(doc);
     }
@@ -103,6 +111,10 @@ public class SearchLog extends BsSearchLog implements SearchLogEvent {
         return searchFieldLogList;
     }
 
+    public List<Pair<String, String>> getRequestHeaderList() {
+        return headerList;
+    }
+
     public void addField(final String key, final Object value) {
         fields.put(key, value);
     }
@@ -120,6 +132,9 @@ public class SearchLog extends BsSearchLog implements SearchLogEvent {
         final Map<String, List<String>> searchFieldMap = searchFieldLogList.stream()
                 .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
         sourceMap.put("searchField", searchFieldMap);
+        final Map<String, List<String>> headerMap = headerList.stream()
+                .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
+        sourceMap.put("headers", headerMap);
         sourceMap.put("documents", documentList);
         return sourceMap;
     }
@@ -142,12 +157,12 @@ public class SearchLog extends BsSearchLog implements SearchLogEvent {
 
     @Override
     public String toString() {
-        return "SearchLog [searchFieldLogList=" + searchFieldLogList + ", userInfo=" + userInfo + ", fields=" + fields + ", accessType="
-                + accessType + ", clientIp=" + clientIp + ", hitCount=" + hitCount + ", languages=" + languages + ", queryId=" + queryId
-                + ", queryOffset=" + queryOffset + ", queryPageSize=" + queryPageSize + ", queryTime=" + queryTime + ", referer=" + referer
-                + ", requestedAt=" + requestedAt + ", responseTime=" + responseTime + ", roles=" + Arrays.toString(roles) + ", searchWord="
-                + searchWord + ", user=" + user + ", userAgent=" + userAgent + ", userInfoId=" + userInfoId + ", userSessionId="
-                + userSessionId + ", virtualHost=" + virtualHost + ", documents=" + documentList + "]";
+        return "SearchLog [searchFieldLogList=" + searchFieldLogList + ", headerList=" + headerList + ", userInfo=" + userInfo + ", fields="
+                + fields + ", accessType=" + accessType + ", clientIp=" + clientIp + ", hitCount=" + hitCount + ", languages=" + languages
+                + ", queryId=" + queryId + ", queryOffset=" + queryOffset + ", queryPageSize=" + queryPageSize + ", queryTime=" + queryTime
+                + ", referer=" + referer + ", requestedAt=" + requestedAt + ", responseTime=" + responseTime + ", roles="
+                + Arrays.toString(roles) + ", searchWord=" + searchWord + ", user=" + user + ", userAgent=" + userAgent + ", userInfoId="
+                + userInfoId + ", userSessionId=" + userSessionId + ", virtualHost=" + virtualHost + ", documents=" + documentList + "]";
     }
 
     @Override
diff --git a/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java b/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
index e94ff0333..a832ad4c0 100644
--- a/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
@@ -20,8 +20,10 @@ import static org.codelibs.core.stream.StreamUtil.stream;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Queue;
 import java.util.concurrent.ConcurrentLinkedQueue;
@@ -109,7 +111,8 @@ public class SearchLogHelper {
         final UserInfoHelper userInfoHelper = ComponentUtil.getUserInfoHelper();
         final SearchLog searchLog = new SearchLog();
 
-        if (ComponentUtil.getFessConfig().isUserInfo()) {
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        if (fessConfig.isUserInfo()) {
             final String userCode = userInfoHelper.getUserCode();
             if (userCode != null) {
                 searchLog.setUserSessionId(userCode);
@@ -164,7 +167,7 @@ public class SearchLogHelper {
         @SuppressWarnings("unchecked")
         final Map<String, List<String>> fieldLogMap = (Map<String, List<String>>) request.getAttribute(Constants.FIELD_LOGS);
         if (fieldLogMap != null) {
-            final int queryMaxLength = ComponentUtil.getFessConfig().getQueryMaxLengthAsInteger();
+            final int queryMaxLength = fessConfig.getQueryMaxLengthAsInteger();
             for (final Map.Entry<String, List<String>> logEntry : fieldLogMap.entrySet()) {
                 for (final String value : logEntry.getValue()) {
                     searchLog.addSearchFieldLogValue(logEntry.getKey(), StringUtils.abbreviate(value, queryMaxLength));
@@ -172,6 +175,15 @@ public class SearchLogHelper {
             }
         }
 
+        LaRequestUtil.getOptionalRequest().ifPresent(req -> {
+            for (final String s : fessConfig.getSearchlogRequestHeadersAsArray()) {
+                final String key = s.replace('-', '_').toLowerCase(Locale.ENGLISH);
+                Collections.list(req.getHeaders(s)).stream().forEach(v -> {
+                    searchLog.addRequestHeaderValue(key, v);
+                });
+            }
+        });
+
         addDocumentsInResponse(queryResponseList, searchLog);
 
         searchLogQueue.add(searchLog);
diff --git a/src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java b/src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java
index bd48921a2..4e56be8a6 100644
--- a/src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java
+++ b/src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java
@@ -1256,6 +1256,9 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
     /** The key of the configuration. e.g. -1 */
     String SEARCHLOG_AGG_SHARD_SIZE = "searchlog.agg.shard.size";
 
+    /** The key of the configuration. e.g.  */
+    String SEARCHLOG_REQUEST_HEADERS = "searchlog.request.headers";
+
     /** The key of the configuration. e.g. 100 */
     String THUMBNAIL_HTML_IMAGE_MIN_WIDTH = "thumbnail.html.image.min.width";
 
@@ -5800,6 +5803,21 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
      */
     Integer getSearchlogAggShardSizeAsInteger();
 
+    /**
+     * Get the value for the key 'searchlog.request.headers'. <br>
+     * The value is, e.g.  <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     */
+    String getSearchlogRequestHeaders();
+
+    /**
+     * Get the value for the key 'searchlog.request.headers' as {@link Integer}. <br>
+     * The value is, e.g.  <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     * @throws NumberFormatException When the property is not integer.
+     */
+    Integer getSearchlogRequestHeadersAsInteger();
+
     /**
      * Get the value for the key 'thumbnail.html.image.min.width'. <br>
      * The value is, e.g. 100 <br>
@@ -9312,6 +9330,14 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
             return getAsInteger(FessConfig.SEARCHLOG_AGG_SHARD_SIZE);
         }
 
+        public String getSearchlogRequestHeaders() {
+            return get(FessConfig.SEARCHLOG_REQUEST_HEADERS);
+        }
+
+        public Integer getSearchlogRequestHeadersAsInteger() {
+            return getAsInteger(FessConfig.SEARCHLOG_REQUEST_HEADERS);
+        }
+
         public String getThumbnailHtmlImageMinWidth() {
             return get(FessConfig.THUMBNAIL_HTML_IMAGE_MIN_WIDTH);
         }
@@ -10458,6 +10484,7 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
             defaultMap.put(FessConfig.PAGING_SEARCH_PAGE_SIZE, "10");
             defaultMap.put(FessConfig.PAGING_SEARCH_PAGE_MAX_SIZE, "100");
             defaultMap.put(FessConfig.SEARCHLOG_AGG_SHARD_SIZE, "-1");
+            defaultMap.put(FessConfig.SEARCHLOG_REQUEST_HEADERS, "");
             defaultMap.put(FessConfig.THUMBNAIL_HTML_IMAGE_MIN_WIDTH, "100");
             defaultMap.put(FessConfig.THUMBNAIL_HTML_IMAGE_MIN_HEIGHT, "100");
             defaultMap.put(FessConfig.THUMBNAIL_HTML_IMAGE_MAX_ASPECT_RATIO, "3.0");
diff --git a/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java b/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
index 5d7aeaebe..8cd0bb374 100644
--- a/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
+++ b/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
@@ -2106,4 +2106,11 @@ public interface FessProp {
     default String getFesenType() {
         return getElasticsearchType();
     }
+
+    String getSearchlogRequestHeaders();
+
+    default String[] getSearchlogRequestHeadersAsArray() {
+        return split(getSearchlogRequestHeaders(), ",")
+                .get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).toArray(n -> new String[n]));
+    }
 }
diff --git a/src/main/resources/fess_config.properties b/src/main/resources/fess_config.properties
index a9c553c37..562ce7072 100644
--- a/src/main/resources/fess_config.properties
+++ b/src/main/resources/fess_config.properties
@@ -679,6 +679,7 @@ paging.search.page.size=10
 paging.search.page.max.size=100
 
 searchlog.agg.shard.size=-1
+searchlog.request.headers=
 
 thumbnail.html.image.min.width=100
 thumbnail.html.image.min.height=100
diff --git a/src/main/resources/fess_indices/fess_log.search_log/search_log.json b/src/main/resources/fess_indices/fess_log.search_log/search_log.json
index a2b3fa5bf..3bac41a5b 100644
--- a/src/main/resources/fess_indices/fess_log.search_log/search_log.json
+++ b/src/main/resources/fess_indices/fess_log.search_log/search_log.json
@@ -1,5 +1,13 @@
 {
     "dynamic_templates": [
+      {
+        "headers": {
+          "path_match": "headers.*",
+          "mapping": {
+            "type": "keyword"
+          }
+        }
+      },
       {
         "search_fields": {
           "path_match": "searchField.*",