A drilling machine for drilling variable-thickness on-edge supported wood, plastics material, aluminum panels, comprises a bottom intermittent conveyor for abutting against a bottom edge of a panel and horizontally conveying a panel to be processed to a tool bearing a rotary turret, top horizontal axis vertically movable abutment and guide rollers for abutting against the top edge of the panel and rear vertical axis rollers. for abutting against and guiding the rear surface of the panel.