To prevent punched junk from remaining in a punching raw material by taperedly forming a knife edge part, and moreover forming a punch hole so that the bore of the deep part of a round hole following a hole in the knife edge part may be larger than the bore in the knife edge part.

Since the upper notch 5 of a punch 1 eates into a trimming die 11, and the punch 1 is thereby locked, the punch 1 is not loosened even by shock in punching. A punched junk punched from a punching raw material is pushed by a following punched junk to ascend in the round hole 3 of the punch 1, but since the diameter of the round hole 3 enlarges in a step part 3a, the punch junks inside the round hole 3 are successively pushed up in the round hole 3 without choking up and discharged through a discharge port 4. The punched junk passing through the discharge port 4 is continuously accommodated in the pocket of a die.