PURPOSE: To provide an automatic punch which can position a printing plate accurately on a surface plate and bore reference holes accurately in predetermined positions of the printing plate.

CONSTITUTION: First and second reference pins 8, 7 are both freely movably formed and are held in awaiting positions behind first and second reference positions on a surface plate, of and a printing plate 200 pressed by first and second pusher pins 5, 6 is pushed back to the first and second reference positions against the pushing forces of the first and second pusher pins 5, 6 by the advancing motion of the first and second reference pins 8, 7.