A drilling apparatus for panels of wood, plastics, aluminium or the like, comprises conveyor means for conveying a panel to be processed along a horizontal axis x, in an intermittent manner, to locate the panel at a tool bearing rotary turret, and being characterized in that the apparatus further comprises top horizontal guide means, vertically arranged along an axis y; abutment means at the horizontal guide means, and suitable to translate along an axis z to fit their position to the thickness of the panel being processed; holding means applied to vertical uprights and suitable to form a fixed support wall for the panel being processed, bottom guide means adapted to translate along the axis z, independently from the horizontal guide means, and which can be adjusted depending on the thickness of the panel, which can be different at different regions of the panel itself.