diff --git a/_includes/head.html b/_includes/head.html
index 88cd3ffa..290c1350 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -54,8 +54,9 @@
   {% endif %}
 
   <!-- Favicon -------------------------- -->
-  <link rel="icon" href="/favicon.svg" sizes="any" type="image/svg+xml">
-  <link rel="apple-touch-icon" href="/apple-touch-icon.png"> <!-- 192x192px -->
+  <link rel="icon" href="/img/favicon/favicon.svg" sizes="any" type="image/svg+xml">
+  <link rel="icon" href="/img/favicon/favicon.webp" sizes="512" type="image/webp">
+  <link rel="apple-touch-icon" href="/img/favicon/apple-touch-icon.png"> <!-- 192x192px -->
   <!-- favicon.ico をルートディレクトリにそっと置く。しかしheadには書かない。 -->
 
   <!-- CSS Framework -------------------------- -->
diff --git a/favicon.ico b/favicon.ico
deleted file mode 100644
index f2242925..00000000
Binary files a/favicon.ico and /dev/null differ
diff --git a/favicon.svg b/favicon.svg
deleted file mode 100644
index 032698ee..00000000
--- a/favicon.svg
+++ /dev/null
@@ -1,48 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<svg id="_レイヤー_2" data-name="レイヤー 2" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 56.41 56.41">
-  <defs>
-    <style>
-      .cls-1 {
-        fill: #094;
-      }
-
-      .cls-1, .cls-2, .cls-3, .cls-4 {
-        stroke-width: 0px;
-      }
-
-      .cls-2 {
-        fill: url(#_名称未設定グラデーション_252);
-      }
-
-      .cls-3 {
-        fill: #231815;
-      }
-
-      .cls-4 {
-        fill: #040000;
-      }
-    </style>
-    <linearGradient id="_名称未設定グラデーション_252" data-name="名称未設定グラデーション 252" x1="7.02" y1="24.67" x2="81.58" y2="24.67" gradientUnits="userSpaceOnUse">
-      <stop offset="0" stop-color="#d32087"/>
-      <stop offset=".03" stop-color="#d51c66"/>
-      <stop offset=".07" stop-color="#d7194c"/>
-      <stop offset=".1" stop-color="#d81639"/>
-      <stop offset=".14" stop-color="#d9152d"/>
-      <stop offset=".17" stop-color="#da152a"/>
-      <stop offset="1" stop-color="#d683b4"/>
-      <stop offset="1" stop-color="#e75b33"/>
-      <stop offset="1" stop-color="#e75b33"/>
-      <stop offset="1" stop-color="#ed802e"/>
-    </linearGradient>
-  </defs>
-  <g id="_レイヤー_1-2" data-name="レイヤー 1">
-    <g>
-      <path class="cls-3" d="M46.83,42.84c1.15-1.46,2.14-3.05,2.9-4.77,1.21-2.73,1.88-5.76,1.88-8.92,0-2.21-.37-4.34-1.03-6.33-.99-2.99-2.61-5.69-4.59-8-1.98-2.31-4.33-4.25-6.81-5.72h0s-.01-.01-.01-.01c-2.29-1.29-3.97-2.47-5.21-3.51-.93-.77-1.62-1.47-2.16-2.07-.4-.45-.72-.86-.98-1.22-.2-.27-.37-.52-.54-.75-.13-.17-.25-.34-.38-.51-.1-.12-.21-.24-.33-.36-.18-.18-.4-.35-.67-.48C28.63.06,28.32,0,28.04,0c-.2,0-.41.03-.61.09-.19.06-.36.15-.52.25-.15.1-.27.2-.39.31-.21.2-.38.42-.54.64-.29.38-.56.8-.94,1.29-.28.37-.62.78-1.05,1.24-.64.68-1.48,1.47-2.62,2.35-1.15.88-2.6,1.86-4.46,2.91h0s-.01.01-.01.01c-3.3,1.96-6.38,4.74-8.66,8.16-1.14,1.71-2.08,3.57-2.74,5.57-.66,1.99-1.03,4.12-1.03,6.33,0,3.17.68,6.18,1.89,8.91.76,1.71,1.74,3.28,2.87,4.74-1.89.87-7.91,4.12-9.23,10.52,12.29,7.02,23.86-.55,26-3.73.27-.08.53-.16.79-.26.16-.06.33-.14.49-.21,1.06.43,2.16.7,3.25.86,2.44,3.27,13.81,10.44,25.88,3.55-1.42-6.89-8.29-10.13-9.58-10.68Z"/>
-      <path class="cls-1" d="M22.75,48.63c-2.26-.1-4.39-.63-6.39-1.59-1.43-.43-2.75-1.04-3.97-1.82h-3.04c-1.53.58-6.44,2.76-7.51,7.06,9.54,4.49,18.54.08,20.87-2.19,0-.49.01-.98.03-1.47Z"/>
-      <path class="cls-4" d="M7.79,51.75l-1.03-1.13c2-2.26,4.02-3.69,5.8-4.58.37.29.78.58,1.2.85.1.07.21.13.32.19-1.83.76-4.06,2.14-6.3,4.67Z"/>
-      <path class="cls-1" d="M32.94,48.63c2.26-.1,4.39-.63,6.39-1.59,1.43-.43,2.75-1.04,3.97-1.82h3.04c1.53.58,6.44,2.76,7.51,7.06-9.54,4.49-18.54.08-20.87-2.19,0-.49-.01-.98-.03-1.47Z"/>
-      <path class="cls-4" d="M46.73,50.4c-1.46-1.46-3.19-2.49-4.69-3.2.52-.32,1.02-.66,1.48-1.02,1.37.73,2.84,1.71,4.17,3.02l-.96,1.2Z"/>
-      <path class="cls-2" d="M46.11,18.41c-4.42-7.18-13.77-9.16-17.88-16.11C22.64,10.93,11.48,11.84,7.93,23.3c-4.16,11.88,6.65,25.98,17.82,23.21,1.12-.36,2.07-1.03,2.84-1.91,3.75-2.76,4.78-9.16,2.33-15.89-.35-.69-.8-1.35-1.38-1.97l.69-.8c-.22.17-.45.32-.68.47l.6-.7c4.81,5.45,4.48,15.78.02,21,13.72,2.99,25.05-15.88,15.94-28.31Z"/>
-    </g>
-  </g>
-</svg>
\ No newline at end of file
diff --git a/img/favicon/apple-touch-icon.png b/img/favicon/apple-touch-icon.png
new file mode 100644
index 00000000..ff74d734
Binary files /dev/null and b/img/favicon/apple-touch-icon.png differ
diff --git a/img/favicon/favicon-192.png b/img/favicon/favicon-192.png
new file mode 100644
index 00000000..ff74d734
Binary files /dev/null and b/img/favicon/favicon-192.png differ
diff --git a/img/favicon/favicon-512.png b/img/favicon/favicon-512.png
new file mode 100644
index 00000000..9f6178e6
Binary files /dev/null and b/img/favicon/favicon-512.png differ
diff --git a/img/favicon/favicon.svg b/img/favicon/favicon.svg
new file mode 100644
index 00000000..5396ba57
--- /dev/null
+++ b/img/favicon/favicon.svg
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+
+<svg
+   width="135.46667mm"
+   height="135.46667mm"
+   viewBox="0 0 135.46667 135.46667"
+   version="1.1"
+   id="svg5"
+   xml:space="preserve"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><defs
+     id="defs2"><style
+       id="style132">
+      .st0 {
+        fill: url(#_gradation_16);
+      }
+    </style><linearGradient
+       id="_gradation_16"
+       data-name="gradation 16"
+       x1="61.450348"
+       y1="193.66197"
+       x2="243.85016"
+       y2="193.66197"
+       gradientUnits="userSpaceOnUse"
+       gradientTransform="matrix(0.27980022,0,0,0.27980022,28.165297,13.546672)"><stop
+         offset="0"
+         stop-color="#c30d23"
+         id="stop134" /><stop
+         offset="1"
+         stop-color="#f29600"
+         id="stop136" /></linearGradient></defs><path
+     class="st0"
+     d="M 83.77329,35.723458 C 76.450762,29.86544 73.52177,23.379779 72.4757,18.777045 c -0.836853,-3.76587 -0.418458,-4.184298 -0.418458,-4.184298 0,-0.418429 -0.418457,-0.836859 -0.627628,-1.046075 h -1.255299 c 0,0 -1.464538,0.209216 -3.765845,2.510579 -5.230373,5.021158 -11.297594,13.598971 -7.322523,25.315006 4.184302,12.552895 2.09215,15.272695 -0.209228,15.063465 -2.928997,-0.20921 -3.347451,-1.88293 -2.928997,-7.531722 0.62762,-6.485672 -5.230371,-11.925254 -5.230371,-11.925254 0,0 -8.996216,14.435826 -16.109574,24.687356 -4.184298,6.06724 -6.276448,13.80819 -6.276448,20.9215 v 0 c 0,21.758338 17.57404,39.332398 39.332377,39.332398 21.758344,0 39.332384,-17.57406 39.332384,-39.332398 1.46454,-18.82934 -8.78704,-35.775754 -23.01364,-47.073363 z M 67.663769,111.04082 c -11.925274,0 -21.758337,-9.62389 -21.758337,-21.758348 0,-12.13446 1.046075,-7.95016 3.138223,-11.08838 1.673696,6.27644 7.322523,10.87918 14.226594,10.87918 6.904066,0 14.645042,-6.48566 14.645042,-14.64506 0,-8.15938 -0.209218,-3.13822 -0.627612,-4.3935 7.113301,3.55666 12.134441,10.87918 12.134441,19.45698 0,11.925248 -9.623907,21.758338 -21.758351,21.758338 z"
+     id="path141"
+     style="fill:url(#_gradation_16);stroke-width:0.2798" /></svg>
diff --git a/img/favicon/favicon.webp b/img/favicon/favicon.webp
new file mode 100644
index 00000000..ccf4c7d5
Binary files /dev/null and b/img/favicon/favicon.webp differ
diff --git a/site.webmanifest b/site.webmanifest
index fb8130c2..4a29e2bf 100644
--- a/site.webmanifest
+++ b/site.webmanifest
@@ -5,16 +5,22 @@
   "name":       "{{ site.title_short }}",
   "short_name": "{{ site.title_short }}",
   "icons": [
-        {
-            "src": "/img/android-chrome-192x192.png",
-            "sizes": "192x192",
-            "type": "image/png"
-        },
-        {
-            "src": "/img/android-chrome-256x256.png",
-            "sizes": "256x256",
-            "type": "image/png"
-        }
+    {
+      "src":   "/img/favicon/favicon-192.png",
+      "sizes": "192x192",
+      "type":  "image/png"
+    },
+    {
+      "src":     "/img/favicon/favicon-512.png",
+      "type":    "image/png",
+      "sizes":   "512x512",
+      "purpose": "maskable"
+    },
+    {
+      "src":   "/img/favicon/favicon-512.png",
+      "sizes": "512x512",
+      "type":  "image/png"
+    }
   ],
   "theme_color":      "#ffffff",
   "background_color": "#ffffff",