WASHING MACHINE

PROBLEM TO BE SOLVED: To provide a washing machine which enhances its cleanliness.SOLUTION: A washing machine comprises: a water tank which is supported in an outer frame in a vibration-proof manner; a washing/dewatering tub which is rotatably provided in the water tank and accommodates laundry therein; a motor which rotatably drives the washing/dewatering tub; a drain passage to which water in the water tank is discharged; a drain valve which is provided at the drain passage; an overflow passage which is connected to the drain passage positioned at a lower side of the drain valve and communicates with the water tank; and an overflow valve which is provided at the overflow passage.