PURPOSE: To enable blanking work on a work at low cost and at high accuracy by holding a punch die and a die by an Oldham's mechanism and providing a guide shaft that fits to the guide of the work and a guide hole of the die in the punch die.

CONSTITUTION: A joining part 74 of a work 71 is positioned and fixed between the punch edge 2 of a punch die 1 and the female edge 15 of a die 14. When the die 1 is lowered, the whole die 1 slides and goes down in the press holder together with a die sleeve 4. Then, guide shafts 9, 10 are inserted to the guide 78 of the work 71. At this time, if there is error in positioning, the die 1 is displaced by an Oldham's mechanism following the shafts 9, 10, and the edge 2 is positioned accurately in the upper part of the joining part 74. When the die 1 goes down further, the shafts 9, 10 are inserted into guide holes 16, 17. The die 14 moves the die holder by the Oldham's mechanism to conform the edge 15 accurately to the edge 2. Then, by lowering of a punch base 3, the joining part 74 is blanked by the edge 2 and edge 15.