PURPOSE: To provide a washing cycle in which a drain water quantity is limited by controlling an opening of a drain valve in a full automatic washing machine.

CONSTITUTION: A signal is sent to a control means 1 at a timing when a two- stage can switch 9 of a motor actuator 3 for actuating a drain valve is actuated, where the opening of the drain valve is set small when a first-stage cam is actuated, while the drain valve is totally opened when a second stage cam is also actuated, so two different drain quantities can be selected according to the design of the two stages of cams. By selecting a washing cycle with the small drain valve opening in washing late at night or early in the morning, the drain quantity is set small, thereby noise of drain water can be prevented.