A method for laser cutting at least a first aperture in a first metal plate in the presence of a second metal plate placed parallel to and a short distance from the first plate and having a second aperture, the outline of which is in line with the outline of the aperture to be cut, wherein a plate forming a protective device, of defined thickness and having a third aperture whose outline is inwardly offset with respect to the outline of the second aperture, is placed between the first and second plates.