diff --git a/11_write_factorytest_by_esptool.sh b/11_write_factorytest_by_esptool.sh
index c308eb5..0768775 100755
--- a/11_write_factorytest_by_esptool.sh
+++ b/11_write_factorytest_by_esptool.sh
@@ -4,8 +4,13 @@
 
 # Get esptool command
 BUILD_TOOL=$(lib_get_esptool_command)
-echo "==="
-echo $BUILD_TOOL
+# BUILD_TOOLの文字列の長さが20以上の場合は、終了する
+if [ ${#BUILD_TOOL} -ge 20 ]; then
+    echo "==="
+    echo "Please execute the script again."
+    echo "==="
+    exit 1
+fi
 
 # Find port - Cross-platform detection
 PORT=$(lib_detect_esptool_port)