A synchronous motor includes a stator, a rotor and permanent magnets. The rotor includes a rotor iron core that is rotatable relative to the stator, and conductor bars accommodated within corresponding slots in the rotor iron core. The conductor bars have their opposite ends short-circuited by respective shortcircuit rings to form a starter cage conductor. The rotor also has a plurality of magnet retaining holes defined therein, in which permanent magnets are embedded. The conductor bar holes are positioned in an axial direction and inwardly from the magnet retaining holes. The conductor bars within the holes protrude outwardly from an axial end of the rotor iron core to form projections for securing an end plate to the end of the rotor iron core, the end plate comprising a non-magnetizable material.