diff --git a/frontend/src/components/WikiBody.tsx b/frontend/src/components/WikiBody.tsx
new file mode 100644
index 0000000..d3d707f
--- /dev/null
+++ b/frontend/src/components/WikiBody.tsx
@@ -0,0 +1,13 @@
+import ReactMarkdown from 'react-markdown'
+import { Link } from 'react-router-dom'
+
+type Props = { body: string }
+
+
+export default ({ body }: Props) => (
+    <ReactMarkdown components={{ a: (
+        ({ href, children }) => (['/', '.'].some (e => href?.startsWith (e))
+                                 ? <Link to={href!}>{children}</Link>
+                                 : <a href={href} target="_blank" rel="noopener noreferrer">{children}</a>)) }}>
+      {body}
+    </ReactMarkdown>)
diff --git a/frontend/src/components/common/TabGroup.tsx b/frontend/src/components/common/TabGroup.tsx
index 4d789cc..45f669a 100644
--- a/frontend/src/components/common/TabGroup.tsx
+++ b/frontend/src/components/common/TabGroup.tsx
@@ -5,7 +5,7 @@ type TabProps = { name:     string
                   init?:    boolean
                   children: React.ReactNode }
 
-type Props = { children: React.ReactElement<{ name: string }>[] }
+type Props = { children: React.ReactElement<TabProps>[] }
 
 export const Tab = ({ children }: TabProps) => <>{children}</>
 
diff --git a/frontend/src/pages/posts/PostListPage.tsx b/frontend/src/pages/posts/PostListPage.tsx
index 7cbda8f..13a6256 100644
--- a/frontend/src/pages/posts/PostListPage.tsx
+++ b/frontend/src/pages/posts/PostListPage.tsx
@@ -1,17 +1,21 @@
 import axios from 'axios'
+import toCamel from 'camelcase-keys'
 import React, { useEffect, useState } from 'react'
 import { Helmet } from 'react-helmet'
 import { Link, useLocation } from 'react-router-dom'
 
 import TagSidebar from '@/components/TagSidebar'
+import WikiBody from '@/components/WikiBody'
+import TabGroup, { Tab } from '@/components/common/TabGroup'
 import MainArea from '@/components/layout/MainArea'
 import { API_BASE_URL, SITE_TITLE } from '@/config'
 
-import type { Post, Tag } from '@/types'
+import type { Post, Tag, WikiPage } from '@/types'
 
 
 export default () => {
   const [posts, setPosts] = useState<Post[]> ([])
+  const [wikiPage, setWikiPage] = useState<WikiPage | null> (null)
 
   const location = useLocation ()
   const query = new URLSearchParams (location.search)
@@ -21,21 +25,20 @@ export default () => {
   const tags = tagsQuery.split (' ').filter (e => e !== '')
 
   useEffect(() => {
-    const fetchPosts = async () => {
-      try
-      {
-        const res = await axios.get (`${ API_BASE_URL }/posts`, {
-            params: { tags:   tags.join (','),
-                      match:  (anyFlg ? 'any' : 'all') } })
-        setPosts (res.data)
-      }
-      catch (error)
-      {
-        console.error ('Failed to fetch posts:', error)
-        setPosts ([])
-      }
-    }
-    fetchPosts()
+    void (axios.get (`${ API_BASE_URL }/posts`, {
+              params: { tags:   tags.join (','),
+                        match:  (anyFlg ? 'any' : 'all') } })
+          .then (res => setPosts (res.data))
+          .catch (err => {
+            console.error ('Failed to fetch posts:', err)
+            setPosts ([])
+          }))
+
+    if (!(tags.length))
+      return
+    void (axios.get (`${ API_BASE_URL }/wiki/title/${ encodeURIComponent (tags.join (' ')) }`)
+          .then (res => setWikiPage (toCamel (res.data, { deep: true })))
+          .catch (() => setWikiPage (null)))
   }, [location.search])
 
   return (
@@ -49,16 +52,30 @@ export default () => {
         </Helmet>
         <TagSidebar posts={posts} />
         <MainArea>
-          <div className="flex flex-wrap gap-4 p-4">
-            {posts.map (post => (
-              <Link to={`/posts/${ post.id }`}
-                    key={post.id}
-                    className="w-40 h-40 overflow-hidden rounded-lg shadow-md hover:shadow-lg">
-                <img src={post.thumbnail ?? post.thumbnail_base}
-                     className="object-none w-full h-full" />
-              </Link>
-            ))}
-          </div>
+          <TabGroup key={wikiPage}>
+            <Tab name="広場">
+              {posts.length
+               ? (
+                  <div className="flex flex-wrap gap-4 p-4">
+                    {posts.map (post => (
+                      <Link to={`/posts/${ post.id }`}
+                            key={post.id}
+                            className="w-40 h-40 overflow-hidden rounded-lg shadow-md hover:shadow-lg">
+                        <img src={post.thumbnail ?? post.thumbnail_base}
+                             className="object-none w-full h-full" />
+                      </Link>
+                    ))}
+                  </div>)
+               : '広場には何もありませんよ．'}
+            </Tab>
+            {(wikiPage && wikiPage.body) && (
+                <Tab name="Wiki" init={!(posts.length)}>
+                  <WikiBody body={wikiPage.body} />
+                  <div className="my-2">
+                    <Link to={`/wiki/${ wikiPage.title }`}>Wiki を見る</Link>
+                  </div>
+                </Tab>)}
+          </TabGroup>
         </MainArea>
       </>)
 }
diff --git a/frontend/src/pages/wiki/WikiDetailPage.tsx b/frontend/src/pages/wiki/WikiDetailPage.tsx
index a3cff73..c60b8a3 100644
--- a/frontend/src/pages/wiki/WikiDetailPage.tsx
+++ b/frontend/src/pages/wiki/WikiDetailPage.tsx
@@ -2,9 +2,9 @@ import axios from 'axios'
 import toCamel from 'camelcase-keys'
 import { useEffect, useState } from 'react'
 import { Helmet } from 'react-helmet'
-import ReactMarkdown from 'react-markdown'
 import { Link, useLocation, useParams, useNavigate } from 'react-router-dom'
 
+import WikiBody from '@/components/WikiBody'
 import PageTitle from '@/components/common/PageTitle'
 import MainArea from '@/components/layout/MainArea'
 import { API_BASE_URL, SITE_TITLE } from '@/config'
@@ -61,15 +61,9 @@ export default () => {
             </div>)}
         <PageTitle>{title}</PageTitle>
         <div className="prose mx-auto p-4">
-          {wikiPage === undefined ? 'Loading...' : (
-              <>
-                <ReactMarkdown components={{ a: (
-                    ({ href, children }) => (['/', '.'].some (e => href?.startsWith (e))
-                                             ? <Link to={href!}>{children}</Link>
-                                             : <a href={href} target="_blank" rel="noopener noreferrer">{children}</a>)) }}>
-                  {wikiPage?.body || `このページは存在しません。[新規作成してください](/wiki/new?title=${ title })。`}
-                </ReactMarkdown>
-              </>)}
+          {wikiPage === undefined
+           ? 'Loading...'
+           : <WikiBody body={wikiPage?.body || `このページは存在しません。[新規作成してください](/wiki/new?title=${ title })。`} />}
         </div>
       </MainArea>)
 }