A washing machine includes a tub. The washing machine includes a drum rotationally provided inside the tub to receive an object to be washed. The washing machine also includes a pulsator rotationally provided inside the drum. The washing machine further includes an outer shaft connected to the drum and including a cavity. The washing machine also includes an inner shaft connected to the pulsator and arranged in the cavity. The washing machine further includes a first pulley including a first axial coupler to be coupled to the outer shaft. The washing machine also includes a second pulley including a second axial coupler protruding toward the tub. The second axial coupler arranged in the cavity and coupled to the inner shaft.