Provided are a washing machine motor including: an outer shaft connected to a washing tub; an inner shaft rotatably disposed inside the outer shaft and connected to a pulsator; an inner rotor connected to the outer shaft; an outer rotor connected to the inner shaft; a stator disposed between the inner rotor and the outer rotor with an air gap; and a planetary gear setmounted on the inner shaft so as to reduce a rotational speed. The washing machine motor includes the planetary gear set which increases a torque by reducing a rotational speed in the inner shaft connected to the pulsator to thereby allow implementation of a large-capacity washing machine.