Hitherto, in order to manufacture a surface magnet rotary electric machine at low cost, a combination of a rotor core having a perfectly circular cross section and a plate-shaped permanent magnet having a flat bonding surface has been used. It is difficult to bond the permanent magnet having the flat bonding surface to an outer peripheral surface of the rotor core having the perfectly circular cross section with highly accurate positioning of the permanent magnet. Therefore, retaining portions each having a polygonal columnar shape are provided to ends of the rotor core in an axial direction of the rotor core (see, for example, Patent Literature 1).