An induction motor which is improved in power factor and reduced in noise and stray loss by specifying the ranges of dimensions of a plurality of slots provided in the rotor core. The slots (3) are arranged on the outer periphery of the rotor core (2) at prescribed intervals in the circumferential direciton, and extended in the axial direction. The dimension of the slots in the circumferential direction lies in a range from 2.0 mm to 3.5 mm, and the dimension of the same in the axial direction in a range from 1.0 mm to 2.5 mm.
