PURPOSE: To produce a rotor having excellent magnetic characteristics and dimensional accuracy in the stage of producing a rotor for a stepping motor with a sintered body by a powder metallurgical method by using IR rays in heating the sintered body for the purpose of performing magnetical annealing after sintering and sizing.

CONSTITUTION: A rotor for a stepping motor is produced by molding and sintering by a powder metallubrical method. The sintered body is subjected to sizing to 7.2W7.6g/cc specific gravity, and further a coating layer consisting essentially of black Fe3O4 is provided on the surface by a steam treatment. Such sintered body is heated quickly at 700W1,000°C by IR irradiation with an IR lamp, whereafter the sintered body is cooled quickly to anneal magnetically the sintered body. Since the black Fe3O4 is coated on the sintered body, the absorptivity of IR rays is good, and the rotor for a stepping motor having the excellent magnetic characteristics at the tips of teeth of the rotor and high dimensional accuracy of the teeth is obtd.