Patent ID: 8291731

Claim:
A washing machine, comprising: a tub for containing water; a storage part depressed in a concave shape from an inner surface of the tub to contain the water; a drum; a heater installed in the storage part; a water supplying valve; a water level sensor installed in the tub to detect a water level; a circulation pump connected with the storage part to draw the water from the tub and then to pump the water to an upper space of the tub; and a controller for controlling the heater according to a detection result by the water level sensor so as to heat the water in the tub and generate steam for washing laundry and controlling the circulation pump, wherein the controller controls the water supplying valve to supply water up to a water level which allows laundry on the bottom of the drum to be soaked for soaking the laundry (“a” level) and below the water level for generating steam (“b”) level) and wherein the controller controls the heater and the circulation pump in a process of swelling the laundry to heat the water by using the heater and circulate the hot water heated by the heater to the tub by using the circulation pump and then supplying the steam generated by the heater to the tub.