The method of spin-forming and spin-forming apparatus

Spin-forming method of the present invention comprises a first molding step for molding and a second molding step in that the plate is fixed to the main shaft (W) while rotating. In the first molding step, the processing tool and the sheet material (W), a first main surface (S1) abuts, so that the first step portion toward the second main surface (S2) from the first main surface (S1) ( 41) shaped. In the second molding step, a position in the first step compared to the portion (41) on the outer periphery side of the processing tool and the second main surface (S2) abuts the opposite direction so that the first stepped portion (41) a second step portion (51) shaped.