diff --git a/bytable.cabal b/bytable.cabal
--- a/bytable.cabal
+++ b/bytable.cabal
@@ -2,7 +2,7 @@
 build-type:	Simple
 
 name:		bytable
-version:	0.0.0.5
+version:	0.0.0.6
 stability:	Experimental
 author:		Yoshikuni Jujo <PAF01143@nifty.ne.jp>
 maintainer:	Yoshikuni Jujo <PAF01143@nifty.ne.jp>
@@ -28,10 +28,10 @@
 source-repository	this
     type:	git
     location:	git://github.com/YoshikuniJujo/forest
-    tag:	bytable-0.0.0.5
+    tag:	bytable-0.0.0.6
 
 library
     hs-source-dirs:	src
     exposed-modules:	Codec.Bytable, Codec.Bytable.BigEndian
-    build-depends:	base == 4.*, bytestring == 0.10.*
+    build-depends:	base == 4.*, bytestring == 0.10.*, word24 == 1.0.*
     ghc-options:	-Wall
diff --git a/src/Codec/Bytable/BigEndian.hs b/src/Codec/Bytable/BigEndian.hs
--- a/src/Codec/Bytable/BigEndian.hs
+++ b/src/Codec/Bytable/BigEndian.hs
@@ -4,6 +4,7 @@
 
 import Data.Bits
 import Data.Word
+import Data.Word.Word24
 import Codec.Bytable
 import qualified Data.ByteString as BS
 
@@ -24,6 +25,13 @@
 		| otherwise = Left
 			"Codec.Bytable.BigEndian: Bytable Word16: too large"
 	toByteString = integralToByteStringN 2
+
+instance Bytable Word24 where
+	fromByteString bs
+		| BS.length bs <= 3 = Right $ byteStringToNum bs
+		| otherwise = Left
+			"Codec.Bytable.BigEndian: Bytable Word24: too large"
+	toByteString = integralToByteStringN 3
 
 instance Bytable Word32 where
 	fromByteString bs