PURPOSE: To prevent a drill from breaking, and to improve a work accuracy, by installing a bush to a pressure foot, inserting the edge tip of a drill into the drilling hole of the bush, and performing perforating on a work by the drill with the work being depression-fixed with the drill hole open edge part of the bush.

CONSTITUTION: A bush 7 is installed detachably to the lower end of a pressure foot 4. At a perforating time the bush 7 is pressed by the pressure foot 4, a printed wiring board 5 which is a work is fixed with its depressing by the bush 7, and perforating is performed by a drill 3. The bush 7 has a hole 8b having the diameter larger than the edge tip diameter of the drill 3 for perforating on the center shaft of the drill, and the edge tip of the drill 3 and bush 7 are not brought into contact. Consequently the hole positional accuracy is improved, and also the drill 3 breakage at the time when the drill 3 is pulled out of the work 5 can be prevented.