According to the disclosed motor, since the motor includes a rotor in which a plurality of core pieces and magnets are alternately arranged in the circumferential direction, magnetic flux of the magnets is prevented from flowing between the core pieces neighbored with each other in the circumferential direction and the leakage of the magnetic flux can be minimized. Since identical polarities of the magnets neighbored with each other in the circumferential direction face each other, the magnetic flux can be concentrated to the respective core pieces. Moreover, since the axial direction of the circumference of the core facing the stator in the circumferential direction is longer than the axial direction of other portions thereof, torque is increased and manufacturing costs are reduced.