A rotor has flux barrier groups. The number of flux barrier groups corresponds to the number of poles, and each of the flux barrier groups has a plurality of arc-shaped flux barriers. The plurality of flux barriers of each flux barrier group include arc-shaped portions formed in a polygonal region that is surrounded by a polygon having vertices at the midpoints in the circumferential direction of the flux barrier groups which are located on the outer peripheral edge of the rotor, as viewed in plan in the direction along a rotor shaft of the rotor. The center of the arcs of the arc-shaped portions of each flux barrier group is located at the midpoint in the circumferential direction of that flux barrier group which is located on the outer peripheral edge of the rotor.