Abstract: In manufacturing a DC motor body (1) including a motor magnet (2), conventionally, a magnetized magnet (2) is fitted to one by one to the cylindrical molding core (11) and a motor body is injection-molded within a cavity formed between a motor body forming mold (10) and a cylindrical molding core (11) to which the magnet is attached. Therefore, the magnet should previously be molded and stocked before molding the motor body, thus not being applicable to mass-production processes. To overcome the above problems, the motor magnet (2) and the motor body (1) are molded in sequence in accordance with two separate molding steps by the use of the same molding core. This method can eliminate troublesome magnetic fitting work, the need of magnet stock and enhance the dimensional precision of motor magnet, thus being applicable to mass-production process while increasing the energy transduction efficiency of the DC motor.