A rotor of a motor includes a plurality of sets of permanent magnets 8a, 8b embedded in the rotor. Each includes a permanent magnet at an inner side and another permanent magnet at an outer side with a distance between them. Each permanent magnet 8a, 8b is formed like an arch projecting towards the center of the rotor. Magnetic flux flows easily through an interval between the permanent magnets at inner and outer sides, and the inductance in a q-axis is enlarged. Then, the reluctance torque is generated in addition to the magnet torque, and the motor has a high torque and a high output power.