PURPOSE: To easily align a pierce punch with a button die by engraving a mark with a marking punch on the mounting surface of the pierce punch of a slide cam and aligning the center of the pierce punch to a mark position to fix a retainer.

CONSTITUTION: A center marking punch 21 is set to the mounting position of the button die 3 of a lower die 2. Then, an upper die 4 is approached to bring the tip of a marking center punch 21 into contact with the mounting surface 5a of the pierce punch of the upper die 4 and to engrave the mark. Then, the central line of the pierce punch is aligned to the position of this mark to fix a retainer 6 to fix the pierce punch 7 to the upper die 4. Consequently, the pierce punch 7 and the button die 3 can be aligned easily with each other.