PURPOSE: To decrease cutting resistance and to increase cutting speed by a method in which an uneven part is formed on the cutting edge of at least either a punching edge or a stationary edge, and the cutting by each part on the cutting edge is performed under staggered-timing manner.

CONSTITUTION: The tip of a punching edge 36 is inclined to a stationary edge 37 with a nip angle θ and has wavy shape 38, i.e. the crests 38a and troughs 38b on the punching edge are formed for the tip of the stationary edge 37, whereby the cutting is performed under staggered-timing manner. Consequently, as the whole parts of the cutting edge are not simultaneously cut, cutting resistance is reduced. Owing to the corrugated shape of the tip, the slippage of the metal sheet can be prevented and cutting speed is increased.