Provided is a washing machine motor including: an outer rotor connected with an outer shaft; an inner rotor connected with an inner shaft; a stator disposed with an air gap between the inner rotor and the outer rotor and driving the inner rotor and the outer rotor independently; and a planetary gear set provided in the inner shaft to thus decelerate a rotational speed of the inner shaft. The outer shaft is rotated at the same speed as that of the outer rotor, and the inner shaft is decelerated compared to the rotational speed of the inner rotor, so as to increase the torque of the inner shaft. The washing machine motor enables a small-torque output from the inner rotor to drive the pulsator through a planetary gear set and a large-torque output from the outer rotor to drive the wash tub through the planetary gear set.
