diff --git a/CHANGELOG.md b/CHANGELOG.md
index 554e54f..0337c3e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ Record of the modification in project development.
 ## [Unreleased] - yyyy-mm-dd
 ### Added
 - [Issue 31 : Add extra partition functionality.](https://github.com/suikan4github/kaiten-yaki/issues/31)
-- [Issue 35 : Support "M/G/T" as size prefix.](https://github.com/suikan4github/kaiten-yaki/issues/35)
+- [Issue 33 : Support "M/G/T" as size prefix.](https://github.com/suikan4github/kaiten-yaki/issues/33)
 
 ### Changed
 ### Deprecated
@@ -15,6 +15,7 @@ Record of the modification in project development.
 
 ### Fixed
 - [Issue 32 : Ubuntu 22.04 fails to deactivate the swap](https://github.com/suikan4github/kaiten-yaki/issues/32)
+- [Issue 36 : Clear the PASSPHRASE variable at the end of installation](https://github.com/suikan4github/kaiten-yaki/issues/36)
 
 ### Known Issue
 
diff --git a/script/lib/common.sh b/script/lib/common.sh
index c37b0f9..2a34de0 100644
--- a/script/lib/common.sh
+++ b/script/lib/common.sh
@@ -139,6 +139,9 @@ function confirmation(){
 		...Installation process terminated..
 		HEREDOC
 		return 1 # with error status
+	else
+		# Clear the PASSPHRASE for checking because we don't use it anymore. 
+		PASSPHRASE_C=""
 	fi	# passphrase validation
 
 	
diff --git a/script/ubuntu-kaiten-yaki.sh b/script/ubuntu-kaiten-yaki.sh
index 7b932e3..e3b4b5d 100644
--- a/script/ubuntu-kaiten-yaki.sh
+++ b/script/ubuntu-kaiten-yaki.sh
@@ -67,8 +67,14 @@ function main() {
 	post_install
 
 	# Free LUKS volume as swap volume.
+	echo "...Disabling swap to release the LUKS volume."
 	swapoff -a
 
+	# Deleting the passphrase information. 
+	echo "...Deleting passphrase information."
+	PASSPHRASE=""
+	export PASSPHRASE
+
 	# Normal end
 	return 0
 
diff --git a/script/void-kaiten-yaki.sh b/script/void-kaiten-yaki.sh
index d31adcc..a49a378 100644
--- a/script/void-kaiten-yaki.sh
+++ b/script/void-kaiten-yaki.sh
@@ -82,8 +82,14 @@ function main() {
 	post_install
 
 	# Free LUKS volume as swap volume.
+	echo "...Disabling swap to release the LUKS volume."
 	swapoff -a
 
+	# Deleting the passphrase information. 
+	echo "...Deleting passphrase information."
+	PASSPHRASE=""
+	export PASSPHRASE
+
 	# Normal end
 	return 0