PURPOSE: To obtain products without burrs by leaving a part where a thick metal plate is not completely punched out by a punch and breaking such part by the next process.

CONSTITUTION: Instead of punching out completely by a punch in one process, the punch is stopped at the position where the forward end face of the punch is slightly bitter downward from the top face of the die. At this time, the part T which is not punched out is generated on the upper edge of the shearing surface of the product, and this part T is in the state of being connected to the thick plate 3, the material. After this first process, the product P is taken out which is still connected to the thick plate 3, set in the punching machine of a second process, and pressed down with the punch to break the part T. Consequently, although sagging is caused on the smooth shearing surface, broken surface and lower side of the product P, burrs are not caused on the upper side, and also with the height of the shearing surface being high, the finish is clean.