at the front inner wall of the cabinet 2 both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 or integrally formed with both sides inner wall of the cabinet 2 thus to be prolonged herein since both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 a diameter of the tub 4 can be increased also the supporting plate 12 is positioned at the rear side of the tub 4 and the gasket 14 is installed between the supporting plate 12 and the rear side of the tub 4 thereby preventing washing water filled in the tub 4 from being leaked the gasket 14 is formed as a bellows of a cylinder shape and has one side fixed to the rear side of the tub 4 and another side fixed to an outer circumference surface of the supporting plate 12 the supporting plate 12 is formed as a disc shape the driving motor 8 is fixed to the rear surface thereof and a rotation shaft 16 for transmitting a rotation force of the driving motor 8 to the drum 6 is rotatably supported by the supporting plate 12 also a supporting unit for supporting the drum 6 with buffering is installed between the supporting plate 12 and the inner wall of the cabinet 2 the supporting unit comprises a plurality of upper supporting rods 22.