diff --git a/content/treestyletab/config.js b/content/treestyletab/config.js
index a573a8f5..ec0da058 100644
--- a/content/treestyletab/config.js
+++ b/content/treestyletab/config.js
@@ -149,14 +149,18 @@ function onChangeTabbarPosition(aOnChange)
 }
 
 
-var gAutoHideModeRadio;
-var gAutoHideModeToggle;
-
+var gAutoHideModeRadio,
+	gAutoHideModeToggle,
+	gTabbarTransparencyScale,
+	gTabbarTransparencyLabels;
 function initAutoHidePane()
 {
 	gAutoHideModeRadio = document.getElementById('extensions.treestyletab.tabbar.autoHide.mode-radio');
 	gAutoHideModeToggle = document.getElementById('extensions.treestyletab.tabbar.autoHide.mode.toggle');
+	gTabbarTransparencyScale = document.getElementById('tabbarTransparency-scale');
+	gTabbarTransparencyLabels = document.getElementById('tabbarTransparency-labels');
 	updateAutoHideModeLabel();
+	onTabbarTransparencyScaleChange();
 }
 
 function onChangeAutoHideMode()
@@ -184,6 +188,12 @@ function updateAutoHideModeLabel()
 		});
 }
 
+function onTabbarTransparencyScaleChange()
+{
+	gTabbarTransparencyLabels.selectedIndex = gTabbarTransparencyScale.value;
+}
+
+
 function updateCloseRootBehaviorCheck()
 {
 	var closeParentBehavior = document.getElementById('extensions.treestyletab.closeParentBehavior-radiogroup').value;
diff --git a/content/treestyletab/config.xul b/content/treestyletab/config.xul
index b93e498a..df14db78 100644
--- a/content/treestyletab/config.xul
+++ b/content/treestyletab/config.xul
@@ -555,12 +555,19 @@
 		</groupbox>
 		<groupbox orient="vertical">
 			<caption label="&config.transparent.style.caption;"/>
-			<radiogroup orient="horizontal"
-				preference="extensions.treestyletab.tabbar.transparent.style">
-				<radio label="&config.transparent.style.0;" value="0"/>
-				<radio label="&config.transparent.style.1;" value="1"/>
-				<radio label="&config.transparent.style.2;" value="2"/>
-			</radiogroup>
+			<hbox align="center">
+				<scale id="tabbarTransparency-scale"
+					preference="extensions.treestyletab.tabbar.transparent.style"
+					orient="horizontal"
+					min="0"
+					max="2"
+					onchange="onTabbarTransparencyScaleChange()"/>
+				<deck id="tabbarTransparency-labels">
+					<label value="&config.transparent.style.0;" control="tabbarTransparency-scale"/>
+					<label value="&config.transparent.style.1;" control="tabbarTransparency-scale"/>
+					<label value="&config.transparent.style.2;" control="tabbarTransparency-scale"/>
+				</deck>
+			</hbox>
 		</groupbox>
 
 	</vbox>
diff --git a/locale/en-US/treestyletab/treestyletab.dtd b/locale/en-US/treestyletab/treestyletab.dtd
index 1739ac89..eafe92c4 100644
--- a/locale/en-US/treestyletab/treestyletab.dtd
+++ b/locale/en-US/treestyletab/treestyletab.dtd
@@ -99,7 +99,7 @@
 <!ENTITY config.autoShow.feedback.delay.before "Hide after">
 <!ENTITY config.autoShow.feedback.delay.after  "msec.">
 
-<!ENTITY config.transparent.style.caption "Background of tab bar">
+<!ENTITY config.transparent.style.caption "Background transparency of tab bar">
 <!ENTITY config.transparent.style.0 "Solid">
 <!ENTITY config.transparent.style.1 "Half-transparent">
 <!ENTITY config.transparent.style.2 "Transparent">
diff --git a/locale/ja/treestyletab/treestyletab.dtd b/locale/ja/treestyletab/treestyletab.dtd
index 3c1d3389..3c0983c8 100644
--- a/locale/ja/treestyletab/treestyletab.dtd
+++ b/locale/ja/treestyletab/treestyletab.dtd
@@ -99,7 +99,7 @@
 <!ENTITY config.autoShow.feedback.delay.before "">
 <!ENTITY config.autoShow.feedback.delay.after  "ミリ秒後に自動で隠す">
 
-<!ENTITY config.transparent.style.caption "自動で隠す時のタブバーの背景">
+<!ENTITY config.transparent.style.caption "自動で隠す時のタブバーの背景の透明度">
 <!ENTITY config.transparent.style.0 "透過しない">
 <!ENTITY config.transparent.style.1 "半透明">
 <!ENTITY config.transparent.style.2 "完全な透明">