Abstract: A washing machine pumps a washing liquid towards an upper portion of a spin tub while a washing cycle is being executed. The washing machine has a pumping unit disposed at an underside of an outer tub so as to pump the washing liquid from a bottom wall of the outer tub to upper portions of the spin tub and the outer tub. The pumping unit has a receptacle which is fixed to the underside of the outer tub, a disc member which is reciprocated in upward and downward directions within the receptacle, a wire having a first end fixed to a center of an underside of the disc member, a synchronous motor connected to a second end of the wire for pulling the disc member downward, and a compression spring installed in the receptacle for upwardly biasing the disc member.