A rotor includes a rotating shaft and a pair of first and second pole cores fixed on the rotating shaft. Each of the first and second pole cores includes a plurality of magnetic pole claws each having a root portion and a distal end. Each of the magnetic pole claws are configured to have a constant circumferential width at the root portion and taper from the root portion to the distal end. The magnetic pole claws of the first pole core are arranged alternately with those of the second pole core in a circumferential direction of the rotating shaft. Further, at least part of the magnetic pole claws of the first and second pole cores each have at least one chamfered portion formed at a circumferential end of the root portion of the magnetic pole claw so as to extend parallel to an axial direction of the rotating shaft.