diff --git a/.github/workflows/cron_ion_token_test.yml b/.github/workflows/cron_ion_token_test.yml
new file mode 100644
index 0000000000..2b8bc4f595
--- /dev/null
+++ b/.github/workflows/cron_ion_token_test.yml
@@ -0,0 +1,38 @@
+name: Update Cesium Ion access token (test)
+on:
+  schedule:
+    - cron: "0 0 2 * *"
+  workflow_dispatch:
+env:
+  GCS_DOMAIN: gs://test.reearth.dev
+  REEARTH_CONFIG_FILENAME: reearth_config.json
+jobs:
+  update_ion_token:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: google-github-actions/auth@v0
+        with:
+          credentials_json: ${{ secrets.GCP_SA_KEY }}
+      - name: Set up Cloud SDK
+        uses: google-github-actions/setup-gcloud@v0
+      - name: Download reearth config
+        run: gsutil cp "${{ env.GCS_DOMAIN }}/${{ env.REEARTH_CONFIG_FILENAME }}" .
+      - name: Get Cesium Ion token
+        id: ion_token
+        run: |
+          ION_TOKEN=$(\
+            curl https://raw.githubusercontent.com/CesiumGS/cesium/main/packages/engine/Source/Core/Ion.js \
+              | node -e "console.log(\
+                  require('fs')\
+                    .readFileSync(process.stdin.fd)\
+                    .toString()\
+                    .match(/const defaultAccessToken =(\n| ).*\"(.*)\";/)[2]\
+                )"\
+          )
+          echo "token=${ION_TOKEN}" >> $GITHUB_OUTPUT
+      - name: Update Ion token in reearth config
+        run: |
+          echo $(cat ${{ env.REEARTH_CONFIG_FILENAME }} | jq -r '.cesiumIonAccessToken |= "${{ steps.ion_token.outputs.token }}"') > ${{ env.REEARTH_CONFIG_FILENAME }}
+          echo $(cat ${{ env.REEARTH_CONFIG_FILENAME }})
+      - name: Upload reearth config
+        run: gsutil -h "Cache-Control:no-store" cp reearth_config.json "${{ env.GCS_DOMAIN }}/${{ env.REEARTH_CONFIG_FILENAME }}"
diff --git a/.github/workflows/deploy_web_nightly.yml b/.github/workflows/deploy_web_nightly.yml
index 3bd93c5f22..1de1836829 100644
--- a/.github/workflows/deploy_web_nightly.yml
+++ b/.github/workflows/deploy_web_nightly.yml
@@ -26,4 +26,4 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
       - run: tar -xvf reearth-web_nightly.tar.gz
       - name: rsync
-        run: gsutil -m -h "Cache-Control:no-store" rsync -x "^reearth_config\\.json$|^cesium_ion_token\\.txt$" -dr reearth-web/ $GCS_DEST
+        run: gsutil -m -h "Cache-Control:no-store" rsync -x "^reearth_config\\.json$" -dr reearth-web/ $GCS_DEST
\ No newline at end of file
diff --git a/web/cesium_ion_token.txt b/web/cesium_ion_token.txt
deleted file mode 100644
index 567712f1b6..0000000000
--- a/web/cesium_ion_token.txt
+++ /dev/null
@@ -1 +0,0 @@
-eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI2MThmZGJiNi1kMDRlLTQ4ZGMtYjU0Ny0yNTljMjM1NzliN2MiLCJpZCI6MjU5LCJpYXQiOjE3MDkzMDQzNjZ9.7gsbNN-OaPZJ7QwMDB2vdF2geQDd8lMBAEK77_5Qol4
\ No newline at end of file
diff --git a/web/src/services/config/index.ts b/web/src/services/config/index.ts
index f4f1d2441f..a71f3605ae 100644
--- a/web/src/services/config/index.ts
+++ b/web/src/services/config/index.ts
@@ -66,11 +66,6 @@ export default async function loadConfig() {
     ...(await (await fetch("/reearth_config.json")).json()),
   };
 
-  const cesiumIonToken = await loadCesiumIonToken();
-  if (cesiumIonToken) {
-    config.cesiumIonAccessToken = cesiumIonToken;
-  }
-
   const authInfo = getAuthInfo(config);
   if (authInfo?.cognito && authInfo.authProvider === "cognito") {
     configureCognito(authInfo.cognito);
@@ -94,18 +89,6 @@ export default async function loadConfig() {
   window.REEARTH_CONFIG = config;
 }
 
-async function loadCesiumIonToken(): Promise<string> {
-  // updating config JSON by CI/CD sometimes can break the config file, so separate files
-  try {
-    const res = await fetch("/cesium_ion_token.txt");
-    const token = await res.text();
-    return token.trim();
-  } catch (e) {
-    // ignore
-  }
-  return "";
-}
-
 export function config(): Config | undefined {
   return window.REEARTH_CONFIG;
 }