diff --git a/content/treestyletab/config.xul b/content/treestyletab/config.xul
index 58170d03..67456a0b 100644
--- a/content/treestyletab/config.xul
+++ b/content/treestyletab/config.xul
@@ -21,6 +21,9 @@
 			name="extensions.treestyletab.adoptChildrenToGrandParentOnRemoveTab"
 			type="bool"
 			inverted="true"/>
+		<preference id="extensions.treestyletab.focusMode"
+			name="extensions.treestyletab.focusMode"
+			type="int"/>
 		<preference id="browser.link.open_newwindow"
 			name="browser.link.open_newwindow"
 			type="int"/>
@@ -38,6 +41,11 @@
 	<checkbox id="extensions.treestyletab.adoptChildrenToGrandParentOnRemoveTab-check"
 		preference="extensions.treestyletab.adoptChildrenToGrandParentOnRemoveTab"
 		label="&config.adoptChildrenToGrandParentOnRemoveTab;"/>
+	<checkbox id="extensions.treestyletab.focusMode-check"
+		preference="extensions.treestyletab.focusMode"
+		label="&config.focusMode;"
+		onsyncfrompreference="return document.getElementById('extensions.treestyletab.focusMode').value == 0;"
+		onsynctopreference="return document.getElementById('extensions.treestyletab.focusMode-check').checked ? 0 : 1 ;"/>
 	<groupbox>
 		<caption label="&config.open_newwindow.caption;"/>
 		<vbox>
diff --git a/content/treestyletab/treestyletab.js b/content/treestyletab/treestyletab.js
index 50716317..c018b05b 100644
--- a/content/treestyletab/treestyletab.js
+++ b/content/treestyletab/treestyletab.js
@@ -11,6 +11,9 @@ var TreeStyleTabService = {
 	kTWISTY           : 'treestyletab-tab-tree-twisty',
 	kTWISTY_CONTAINER : 'treestyletab-tab-tree-twisty-container',
 
+	kFOCUS_ALL     : 0,
+	kFOCUS_VISIBLE : 1,
+
 	levelMargin : 12,
 
 	NSResolver : {
@@ -40,7 +43,7 @@ var TreeStyleTabService = {
 	_SessionStore : null,
 	 
 /* Utilities */ 
-	
+	 
 	isEventFiredOnTabIcon : function(aEvent) 
 	{
 		var tab = this.getTabFromEvent(aEvent);
@@ -72,6 +75,30 @@ var TreeStyleTabService = {
 		return 'SplitBrowser' ? SplitBrowser.activeBrowser : gBrowser ;
 	},
  
+	evaluateXPath : function(aExpression, aContext, aType) 
+	{
+		if (!aType) aType = XPathResult.ORDERED_NODE_SNAPSHOT_TYPE;
+		try {
+			var xpathResult = document.evaluate(
+					aExpression,
+					aContext,
+					this.NSResolver,
+					aType,
+					null
+				);
+		}
+		catch(e) {
+			return {
+				singleNodeValue : null,
+				snapshotLength  : 0,
+				snapshotItem    : function() {
+					return null
+				}
+			};
+		}
+		return xpathResult;
+	},
+ 
 	getArrayFromXPathResult : function(aXPathResult) 
 	{
 		var max = aXPathResult.snapshotLength;
@@ -165,43 +192,23 @@ var TreeStyleTabService = {
 			separator.setAttribute('hidden', true);
 		}
 	},
-	
+	 
 	getSeparators : function(aPopup) 
 	{
-		try {
-			var xpathResult = document.evaluate(
-					'descendant::xul:menuseparator',
-					aPopup,
-					this.NSResolver,
-					XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
-					null
-				);
-		}
-		catch(e) {
-			return { snapshotLength : 0 };
-		}
-		return xpathResult;
+		return this.evaluateXPath('descendant::xul:menuseparator', aPopup);
 	},
  
 	getObsoleteSeparator : function(aPopup) 
 	{
-		try {
-			var xpathResult = document.evaluate(
-					'descendant::xul:menuseparator[not(@hidden)][not(following-sibling::*[not(@hidden)]) or not(preceding-sibling::*[not(@hidden)]) or local-name(following-sibling::*[not(@hidden)]) = "menuseparator"]',
-					aPopup,
-					this.NSResolver,
-					XPathResult.FIRST_ORDERED_NODE_TYPE,
-					null
-				);
-		}
-		catch(e) {
-			return null;
-		}
-		return xpathResult.singleNodeValue;
+		return this.evaluateXPath(
+				'descendant::xul:menuseparator[not(@hidden)][not(following-sibling::*[not(@hidden)]) or not(preceding-sibling::*[not(@hidden)]) or local-name(following-sibling::*[not(@hidden)]) = "menuseparator"]',
+				aPopup,
+				XPathResult.FIRST_ORDERED_NODE_TYPE
+			).singleNodeValue;
 	},
    
 /* Initializing */ 
-	
+	 
 	init : function() 
 	{
 		if (!('gBrowser' in window)) return;
@@ -238,7 +245,7 @@ var TreeStyleTabService = {
 
 		this.initTabBrowser(gBrowser);
 	},
-	
+	 
 	initTabBrowser : function(aTabBrowser) 
 	{
 		aTabBrowser.mTabContainer.addEventListener('TreeStyleTab:TabOpen', this, true);
@@ -255,8 +262,36 @@ var TreeStyleTabService = {
 				/\{/,
 				<><![CDATA[
 					{
-						if (aNewTab.__treestyletab__preventSelect) {
-							aNewTab.__treestyletab__preventSelect = false;
+						if (arguments[0].__treestyletab__preventSelect) {
+							arguments[0].__treestyletab__preventSelect = false;
+							return;
+						}
+				]]></>
+			)
+		);
+
+		eval('aTabBrowser.mTabContainer.advanceSelectedTab = '+
+			aTabBrowser.mTabContainer.advanceSelectedTab.toSource().replace(
+				/\{/,
+				<><![CDATA[
+					{
+						if (TreeStyleTabService.getPref('extensions.treestyletab.focusMode') == 1) {
+							var xpathResult = TreeStyleTabService.evaluateXPath(
+										(arguments[0] < 0 ? 'preceding-sibling' : 'following-sibling' )+
+											'::xul:tab[not(@'+TreeStyleTabService.kCOLLAPSED+'="true")]',
+										this.selectedItem
+									);
+							var nextTab = xpathResult.snapshotItem(arguments[0] < 0 ? xpathResult.snapshotLength-1 : 0 );
+							if (!nextTab && arguments[1]) {
+								var xpathResult = TreeStyleTabService.evaluateXPath(
+										'child::xul:tab[not(@'+TreeStyleTabService.kCOLLAPSED+'="true")]',
+										this
+									);
+								nextTab = xpathResult.snapshotItem(arguments[0] < 0 ? xpathResult.snapshotLength-1 : 0 );
+							}
+							if (nextTab && nextTab != this.selectedItem) {
+								this.selectNewTab(nextTab, arguments[0], arguments[1]);
+							}
 							return;
 						}
 				]]></>
@@ -313,7 +348,7 @@ var TreeStyleTabService = {
 		delete tabs;
 
 	},
- 
+ 	
 	initTab : function(aTab, aTabBrowser) 
 	{
 		var id = 'tab-<'+Date.now()+'-'+parseInt(Math.random() * 65000)+'>';
@@ -391,7 +426,7 @@ var TreeStyleTabService = {
 	},
    
 /* Event Handling */ 
-	 
+	
 	handleEvent : function(aEvent) 
 	{
 		switch (aEvent.type)
@@ -641,9 +676,9 @@ var TreeStyleTabService = {
 			this.collapseExpandTreesIntelligentlyFor(tab);
 		}
 	},
- 	 
+  
 /* Tab Utilities */ 
-	 
+	
 	getTabValue : function(aTab, aKey) 
 	{
 		var value = null;
@@ -682,37 +717,21 @@ var TreeStyleTabService = {
  
 	getTabById : function(aId, aTabBrowser) 
 	{
-		try {
-			var xpathResult = document.evaluate(
-					'descendant::xul:tab[@'+this.kID+' = "'+aId+'"]',
-					aTabBrowser.mTabContainer,
-					this.NSResolver,
-					XPathResult.FIRST_ORDERED_NODE_TYPE,
-					null
-				);
-		}
-		catch(e) {
-			return null;
-		}
-		return xpathResult.singleNodeValue;
+		return this.evaluateXPath(
+				'descendant::xul:tab[@'+this.kID+' = "'+aId+'"]',
+				aTabBrowser.mTabContainer,
+				XPathResult.FIRST_ORDERED_NODE_TYPE
+			).singleNodeValue;
 	},
  
 	getParentTabOf : function(aTab) 
 	{
 		var id = aTab.getAttribute(this.kID);
-		try {
-			var xpathResult = document.evaluate(
-					'parent::*/child::xul:tab[contains(@'+this.kCHILDREN+', "'+id+'")]',
-					aTab,
-					this.NSResolver,
-					XPathResult.FIRST_ORDERED_NODE_TYPE,
-					null
-				);
-		}
-		catch(e) {
-			return null;
-		}
-		return xpathResult.singleNodeValue;
+		return this.evaluateXPath(
+				'parent::*/child::xul:tab[contains(@'+this.kCHILDREN+', "'+id+'")]',
+				aTab,
+				XPathResult.FIRST_ORDERED_NODE_TYPE
+			).singleNodeValue;
 	},
  
 	getNextSiblingTabOf : function(aTab) 
@@ -832,7 +851,7 @@ var TreeStyleTabService = {
 	},
   
 /* Commands */ 
-	 
+	
 	adoptTabTo : function(aChild, aParent, aInfo) 
 	{
 		if (!aChild || !aParent) return;
@@ -1010,43 +1029,38 @@ var TreeStyleTabService = {
 			expandedParentTabs.push(parentTab.getAttribute(this.kID));
 		}
 		expandedParentTabs = expandedParentTabs.join('|');
-		try {
-			var xpathResult = document.evaluate(
-					'child::xul:tab[@'+this.kCHILDREN+' and not(@'+this.kCOLLAPSED+'="true") and not(@'+this.kSUBTREE_COLLAPSED+'="true") and not(contains("'+expandedParentTabs+'", @'+this.kID+'))]',
-					b.mTabContainer,
-					this.NSResolver,
-					XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
-					null
-				);
-			var collapseTab;
-			var dontCollapse;
-			for (var i = 0, maxi = xpathResult.snapshotLength; i < maxi; i++)
-			{
-				dontCollapse = false;
-				collapseTab  = xpathResult.snapshotItem(i);
 
-				parentTab = this.getParentTabOf(collapseTab);
-				if (parentTab) {
-					dontCollapse = true;
-					do {
-						if (parentTab != parent) continue;
-						dontCollapse = false;
-						break;
-					}
-					while (parentTab = this.getParentTabOf(parentTab));
+		var xpathResult = this.evaluateXPath(
+				'child::xul:tab[@'+this.kCHILDREN+' and not(@'+this.kCOLLAPSED+'="true") and not(@'+this.kSUBTREE_COLLAPSED+'="true") and not(contains("'+expandedParentTabs+'", @'+this.kID+'))]',
+				b.mTabContainer
+			);
+		var collapseTab;
+		var dontCollapse;
+		for (var i = 0, maxi = xpathResult.snapshotLength; i < maxi; i++)
+		{
+			dontCollapse = false;
+			collapseTab  = xpathResult.snapshotItem(i);
+
+			parentTab = this.getParentTabOf(collapseTab);
+			if (parentTab) {
+				dontCollapse = true;
+				do {
+					if (parentTab != parent) continue;
+					dontCollapse = false;
+					break;
 				}
-
-				if (!dontCollapse)
-					this.collapseExpandTabSubTree(collapseTab, true);
+				while (parentTab = this.getParentTabOf(parentTab));
 			}
+
+			if (!dontCollapse)
+				this.collapseExpandTabSubTree(collapseTab, true);
 		}
-		catch(e) {
-		}
+
 		this.collapseExpandTabSubTree(aTab, false);
 	},
   
 /* Pref Listener */ 
-	 
+	
 	domain : 'extensions.treestyletab', 
  
 	observe : function(aSubject, aTopic, aPrefName) 
@@ -1065,7 +1079,7 @@ var TreeStyleTabService = {
 	},
   
 /* Save/Load Prefs */ 
-	 
+	
 	get Prefs() 
 	{
 		if (!this._Prefs) {
diff --git a/defaults/preferences/treestyletab.js b/defaults/preferences/treestyletab.js
index 056909cf..174e7ad0 100644
--- a/defaults/preferences/treestyletab.js
+++ b/defaults/preferences/treestyletab.js
@@ -1,6 +1,8 @@
-pref("extensions.treestyletab.autoCollapseExpandSubTreeOnSelect", true);
-pref("extensions.treestyletab.autoExpandSubTreeOnAppendChild", true);
+pref("extensions.treestyletab.autoCollapseExpandSubTreeOnSelect",     true);
+pref("extensions.treestyletab.autoExpandSubTreeOnAppendChild",        true);
 pref("extensions.treestyletab.adoptChildrenToGrandParentOnRemoveTab", true);
+// 0 = default, 1 = only visible tabs
+pref("extensions.treestyletab.focusMode", 1);
 
 pref("browser.link.open_newwindow.restriction", 0);
 
diff --git a/locale/en-US/treestyletab/treestyletab.dtd b/locale/en-US/treestyletab/treestyletab.dtd
index cbb2b348..935b7757 100644
--- a/locale/en-US/treestyletab/treestyletab.dtd
+++ b/locale/en-US/treestyletab/treestyletab.dtd
@@ -9,6 +9,8 @@
 
 <!ENTITY config.adoptChildrenToGrandParentOnRemoveTab "Liberate child tabs from the tree when the parent tab is closed">
 
+<!ENTITY config.focusMode "Focus to the next/previous tab even if it is invisible, by Control(Command)-Tab">
+
 <!ENTITY config.open_newwindow.caption "New window opened from links in webpages unexpectedly">
 <!ENTITY config.open_newwindow.window  "Open as Window">
 <!ENTITY config.open_newwindow.tab     "Open as Tab (default)">
diff --git a/locale/ja/treestyletab/treestyletab.dtd b/locale/ja/treestyletab/treestyletab.dtd
index d16b996a..331a3db8 100644
--- a/locale/ja/treestyletab/treestyletab.dtd
+++ b/locale/ja/treestyletab/treestyletab.dtd
@@ -9,6 +9,8 @@
 
 <!ENTITY config.adoptChildrenToGrandParentOnRemoveTab "親のタブを閉じたら子孫のタブをツリーから解放する">
 
+<!ENTITY config.focusMode "Control(Command)-Tabでタブを切り替える時、折りたたまれたタブにもフォーカスする">
+
 <!ENTITY config.open_newwindow.caption "Webページのリンクから勝手に開かれたウィンドウの制御">
 <!ENTITY config.open_newwindow.window  "ウィンドウで開く">
 <!ENTITY config.open_newwindow.tab     "タブで開く（初期値）">