To provide a permanent magnet that can reduce the cost and, at the same time, can improve the characteristics of motors, and to provide a rotor for the motor using the magnet.

The permanent magnet 1, such as a magnetically oriented sintered magnet, bonded magnet, etc., is constituted so that the magnet 1 are curved on the upper and lower surfaces 1a and 1b in its transversal cross section. Then magnetizing is made curving around the center of the upper surface 1. In addition, the rotor R of a motor is constituted by arranging a plurality of permanent magnets 1, thus constituted on the outer peripheral surface of the shaft 11 of the motor.