PURPOSE: To prevent foam from overflowing from the upper parts of an inner vessel and an outer vessel while clothing is stirred in a washing process.

CONSTITUTION: An inner vessel 1, for which a pulsator 2 is arranged at a central bottom part so as to be freely rotated, is provided inside an outer vessel 7 and an upper cover 8 is arranged at the upper part of the outer vessel 7 so as to cover the inner vessel 1. Then, a discharge hose 15 is provided to be communication with the outside of the machine through a discharge valve 12 provided at the lower part of the outer vessel 7, and a pipe 14 to be communicated with a hole 13 provided at the upper part of the outer vessel 7 is linked to the discharge hose 15. A driving mechanism part 11 is provided to selectively drive the pulsator 2 or the inner vessel 1 with the driving force of a motor 10 and in the dehydrating process, the inner vessel 1 can be revolved in one direction by the driving mechanism part 1 but in the washing process, the revolution of the inner vessel 1 is controlled. Further, the outer vessel 7 is equipped with an opening part 24 at the upper part of the hole 13, the upper cover 8 corresponds to the revolving direction side of the inner vessel 1 at the opening part 24, and a projecting part 23 is formed toward the central direction of the inner vessel 1.