PURPOSE: To prevent the generation of the deformation and the strain caused on dropping down at the final process by providing a minute semi-punched part at the outer shape of the blank on the blank punching process, and cutting and separating the blank from the blank material side at the drawing process.

CONSTITUTION: In the blank punching of the 1st process, a minute semi-punched part 6 is provided on the outer shape of the blank 2, and the blank 2 is held on the blank material side 4. Next, because the blank 2 is cut and separated from the blank material 4, the generation of the deformation and the strain caused by dropping in the conventional final process is prevented and also the man-hour is reduced.