diff --git a/index.html b/index.html
index 482befa..61c4452 100644
--- a/index.html
+++ b/index.html
@@ -31,11 +31,11 @@
   </head>
 
   <body>
-    <header>
+    <header id="header">
       <img src="assets/images/artboard.svg" width="100%" />
     </header>
 
-    <section class="about">
+    <section id="about" class="about">
       <h1>Osaka RubyKaigi 03</h1>
       <h2>"Rubyで笑おう"</h2>
       <p>
@@ -53,7 +53,7 @@ <h2>"Rubyで笑おう"</h2>
       <a class="round-button" target="_blank" href="https://rubykansai.doorkeeper.jp/events/158794">申し込む</a>
     </section>
 
-    <section class="guest-speaker">
+    <section id="guest-speaker" class="guest-speaker">
       <h1 class="section-title">Guest Speaker</h1>
       <div class="guest-speaker-list">
         <div class="guest-speaker-card">
@@ -88,7 +88,7 @@ <h1 class="section-title">Guest Speaker</h1>
       </div>
     </section>
 
-    <section class="timetable">
+    <section id="timetable" class="timetable">
       <h1 class="section-title">Timetable</h1>
       <ul class="timetable">
         <li class="timetable-event-item">
@@ -344,7 +344,7 @@ <h1 class="section-title">Timetable</h1>
       </ul>
     </section>
 
-    <section class="sponsor">
+    <section id="sponsor" class="sponsor">
       <h1 class="section-title">Sponsor</h1>
       <div class="sponsor-list">
         <a href="https://agileware.jp/careers/" class="sponsor-card" target="_blank" rel="”noopener" noreferrer”>
@@ -481,7 +481,7 @@ <h2 class="sponsor-name">リバティ・フィッシュ株式会社</h2>
         </a>
       </div>
 
-      <h1 class="section-title">In Kind Sponsor</h1>
+      <h1 id="in-kind-sponsor" class="section-title">In Kind Sponsor</h1>
       <div class="sponsor-list">
         <a
           href="https://www.instagram.com/bouquetec_com/"
@@ -507,7 +507,7 @@ <h2 class="sponsor-name">BouqueTec株式会社</h2>
         </a>
       </div>
 
-      <h1 class="section-title">Community Sponsor</h1>
+      <h1 id="community-sponsor" class="section-title">Community Sponsor</h1>
       <div class="sponsor-list">
         <a href="https://ruby-no-kai.org/" class="sponsor-card" target="_blank" rel="noopener noreferrer">
           <div class="sponsor-logo">
@@ -566,7 +566,7 @@ <h2 class="sponsor-name">Ruby Tuesday</h2>
       </div>
     </section>
 
-    <section class="member">
+    <section id="member" class="member">
       <h1 class="section-title">Member</h1>
       <div class="member-list">
         <div class="member-card">
@@ -727,7 +727,7 @@ <h1 class="section-title">Member</h1>
       </div>
     </section>
 
-    <section class="access">
+    <section id="access" class="access">
       <h1 class="section-title">Access</h1>
       <p>
         大阪市中央区西心斎橋1-5-24<br />
@@ -745,7 +745,7 @@ <h1 class="section-title">Access</h1>
       </div>
     </section>
 
-    <section class="footer">
+    <section id="footer" class="footer">
       <a href="https://twitter.com/rubykansai" target="_blank">
         <img src="assets/images/twitter.svg" alt="twitter" />
       </a>
