To improve the operability, reliability and yield of a magnet and to reduce the packing cost at the time of its transportation, by reliably positioning and holding magnetic members before magnetization with respect to a core pin at the time of the injection molding of a body.

In a permanent magnet field motor in which a hollow portion S is formed by the end portions of a core pin during the injection molding of a body 11, and, as a result of the injection molding of the body 11, a plurality of circumferentially arranged magnets are embedded into the circumferential wall of the portion S, so that a rotor 13 is rotatably provided in the portion S, a yoke 3 is disposed around the inner circumferential wall of the portion S of the body 11. The yoke 3 clomps magnet members before magnetizing magnets 1 and 2 between the surfaces confronting the end portions of the core pin, so as to allow the magnet members to be fitted into the outer circumference of the end portions of the core pin during the injection molding of the body 11.