PURPOSE: To realize precision enhancement of printed board perforating, and enhance dust collection efficiency and productivity of perforating.

CONSTITUTION: In a perforator 1 of a printed board, the inside diameter of a pressure foot 4 provided on its lower end is formed to be of the nearly same diameter as the outer circumference of a spindle 3 that supports a drill 2, and at the same time, this pressure foot 4 is provided with a vent hole 5 that communicates with the outside, and further an engaging part 7 on its outer circumference, and, as a bush exchange system of this perforator 1, bushes 6 provided with mounting parts 10 that engage with the engaging part 7 and optimum drill penetrating holes 6a according to the outside diameter of the drill 2 are provided, not less than one and in plural number.