A washing machine includes a dewatering shaft for rotating a washing tub, a drive shaft for rotating a pulsator in the washing tub, a coupler that is configured to move up and down along the dewatering shaft, a solenoid module that moves the coupler upward, a coupler guide configured to be rotated by contact with the coupler when the coupler moves upward, and to maintain a position of the coupler or guide the coupler to another position when the coupler moves downward, and a controller that controls operation of the solenoid module based on applying one or more pulse signals to the solenoid module.