A rotor with four axially stacked rotor cores, and a plurality of field magnets interposed between them. Each rotor core includes a rotor-side claw-shaped magnetic pole. Each rotor-side claw-shaped magnetic poles are respectively extending from and formed on each rotor core at equal angle intervals. Tip end surfaces of the first and third rotor-side claw-shaped magnetic pole abut against or are closely opposed to each other axially. Tip end surfaces of the second and fourth rotor-side claw-shaped magnetic poles abut against or are closely opposed to each other in the axial direction. The plurality of field magnets are magnetized in the axial direction such that the field magnets causes the first and third rotor-side claw-shaped magnetic poles to function as first magnetic poles, and cause the second and fourth rotor-side claw-shaped magnetic poles to function as second magnetic poles.