PURPOSE: To form a deep groove and emboss by one stroke of a punch for the thickness of a work by forming one or both of the shoulder of a punch and the shoulder of a die groove into multiple stepped form.

CONSTITUTION: For instance, the shoulder of a punch 11 is formed into two steps 16, 17 and the shoulder of a die groove is also formed into two steps 18, 19. When a work 4 is placed on a die 12, and the slide of a press machine is lowered, a blank holder 14 pressed and fixes the work 4 on the die face 10. With the punch 14 lowered, the depth of the groove is increased and a groove is formed while causing concentration of stress on a part that connect the shoulder 16 of the punch 11 and the shoulder 18 of the die groove 13 and a part that connects shoulders 17, 19. Thus, a deep groove or emboss is formed for the thickness of the work 4 by one stroke of the punch 11 without rupturing the work 4.