A printed circuit board boring machine bores printed circuit boards stacked on a table, by a drill while pressing the printed circuit boards with a pressure foot. A piece having a hole through which the drill may pass is detachably mounted on a tip end portion of the pressure foot with a center of the hole being aligned with an axis of the drill. The piece may be attached to the pressure foot before the boring work so that the boards and the piece may be simultaneously bored by the drill while the hole in the piece may be used as a guide for the boring work of the boards.