PURPOSE: To decrease the number of processes for die replacement and to improve the rate of operation of a press machine in press dies for cutting process, by providing plural cutting edges to both an upper and a lower die for cutting, rotating the upper and lower dies together, and then switching the cutting edges selectively.

CONSTITUTION: A lower die 11 is fixed to a base plate 10, and an upper die 12 is fixed to a slide 2. Plural lower edges 16a and 16c with differed shapes are formed at a recessed part 15 formed in the lower die 11, and the corresponding upper edges 17a and 17c thereto are formed at the circumference of the upper die 12. A pin 18 is implanted in the center of the base plate 10, and the lower die 11 is rotated around the pin 18. On edges replacement, the lower die 11 and upper die 12 are rotated by a specified angle firstly and a cylinder 19 is operated reversely, thereby positoning the lower die 11 at the plate 10 while a positioning pin 24 corresponds to a positioning hole 25 in such a way that the upper die 11 coincides with the upper die 12. Then, the lower die 11 and upper die 12 are fixed and the slide 2 is elevated, thereby completing the replacement of the cutting edges.