Abstract: The drilling machine has a cross member along which slide two carriages supporting two machining heads; the two carriages are moved independently of each other along the X axis; one of the two machining heads is fitted to the respective carriage by means of a slide which is also moved along the Y axis by an electric motor controlled by a numeric-control unit; the maximum travel of the slide is at least twice the pitch of the rows in the matrix of holes in the printed circuit boards; and the movement of the slide provides for both setting the two machining heads along the Y axis, and enabling the two machining heads to simultaneously drill two adjacent rows in the matrix of holes.