diff --git a/src/main/java/osm/surveyor/task/city/CityController.java b/src/main/java/osm/surveyor/task/city/CityController.java
index 21f68c4..9af28d2 100644
--- a/src/main/java/osm/surveyor/task/city/CityController.java
+++ b/src/main/java/osm/surveyor/task/city/CityController.java
@@ -8,6 +8,7 @@
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.servlet.view.RedirectView;
 
 import lombok.RequiredArgsConstructor;
 import osm.surveyor.task.city.model.City;
@@ -49,4 +50,11 @@
 		repository.deleteByCitycode(citycode);
 		return "redirect:/city";
 	}
+
+	@GetMapping("/howto")
+	public RedirectView howto() {
+		RedirectView redirectView = new RedirectView();
+	    redirectView.setUrl("https://github.com/yuuhayashi/task-bldg/wiki");
+	    return redirectView;
+	}
 }
diff --git a/src/main/resources/templates/fragments/sidebar.html b/src/main/resources/templates/fragments/sidebar.html
index 21eb189..c6cfacf 100644
--- a/src/main/resources/templates/fragments/sidebar.html
+++ b/src/main/resources/templates/fragments/sidebar.html
@@ -67,6 +67,12 @@
                 BLDGデータリスト
               </a>
             </li>
+            <li class="nav-item">
+              <a th:href="@{/howto}" class="nav-link text-white">
+                <i class="bi bi-box-arrow-right me-2"></i>
+                使い方 (外部リンク)
+              </a>
+            </li>
           </ul>
 
           <hr>