A suction motor capable of having reduced axial length is disclosed. The suction motor according to the present invention comprises: a rotary shaft; an impeller fixed to one end of the rotary shaft; a bearing assembly provided at one side of the impeller and rotatably supporting the rotary shaft; a permanent magnet provided on the rotary shaft at one side of the bearing assembly; a weight balancer provided on the other end of the rotary shaft at one side of the permanent magnet; and a stator assembly provided at the circumference of the permanent magnet, wherein the weight balancer is formed such that when the rotary shaft rotates, the impeller, the permanent magnet and the weight balancer achieve rotational balance around the bearing assembly.