A circulatory washing machine, in which water stored in the bottom of a tub is circulated and supplied to a drum. The washing machine includes a tub for containing washing water; a drum rotatably installed in the tub; a circulation unit for circulating the washing water stored in the tub to the upper portion of the drum; and a spray nozzle for spraying the washing water, circulated by the circulation unit, to the rear portion of the inside of the drum.