diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e4e18d..e0a9874 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ Record of the modification in project development.
 ### Deprecated
 ### Removed
 ### Fixed
+- [Issue 24 : Fail to install the ubuntu when the / volume is btrfs](https://github.com/suikan4github/kaiten-yaki/issues/24)
+
 ### Known Issue
 
 ## [1.1.0] - 2021-07-11
diff --git a/script/lib/common.sh b/script/lib/common.sh
index 8fcb0ea..ed5be7d 100644
--- a/script/lib/common.sh
+++ b/script/lib/common.sh
@@ -291,8 +291,11 @@ function para_install_msg() {
 function post_install() {
 	## Mount the target file system
 	# ${TARGETMOUNTPOINT} is created by the GUI/TUI installer
+	# ${BTRFSOPTION} is defined by the caller of this function for BTRFS formated volume.
+	# ${BTRFSOPTION} have to be NOT quoted. Otherwise, mount will receive an empty
+	# string as first option, when the veraible is empty. 
 	echo "...Mounting /dev/mapper/${VGNAME}-${LVROOTNAME} on ${TARGETMOUNTPOINT}."
-	mount /dev/mapper/"${VGNAME}"-"${LVROOTNAME}" "${TARGETMOUNTPOINT}"
+	mount ${BTRFSOPTION} /dev/mapper/"${VGNAME}"-"${LVROOTNAME}" "${TARGETMOUNTPOINT}"
 
 	# And mount other directories
 	echo "...Mounting all other dirs."
diff --git a/script/ubuntu-kaiten-yaki.sh b/script/ubuntu-kaiten-yaki.sh
index 96ace9b..adfbbdd 100644
--- a/script/ubuntu-kaiten-yaki.sh
+++ b/script/ubuntu-kaiten-yaki.sh
@@ -53,6 +53,15 @@ function main() {
 	#                                Post-install stage 
 	# ******************************************************************************* 
 
+	# If the target volume is formated by btrfs, Ubiquity install the root into the
+	# @ sub-volume. Thus, mount command inside post_install have to use special option
+	# to specify @ as mount target. 
+	if lsblk -o NAME,FSTYPE | grep -i "${VGNAME}-${LVROOTNAME}" | grep -i "btrfs" > /dev/null ; then 
+		export BTRFSOPTION="-o subvol=@"
+	else
+		export BTRFSOPTION=""
+	fi
+
 	# Distribution dependent finalizing. Embedd encryption key into the ramfs image.
 	# The script is parameterized by env-variable to fit to the distribution 
 	post_install
diff --git a/script/void-kaiten-yaki.sh b/script/void-kaiten-yaki.sh
index 5838747..c63f906 100644
--- a/script/void-kaiten-yaki.sh
+++ b/script/void-kaiten-yaki.sh
@@ -74,6 +74,9 @@ function main() {
 	#                                Post-install stage 
 	# ******************************************************************************* 
 
+	# We don't need special option for BTRFSOPTION. 
+	export BTRFSOPTION=""
+
 	# Distribution dependent finalizing. Embedd encryption key into the ramfs image. 
 	# The script is parameterized by env-variable to fit to the distribution 
 	post_install