A device for cutting a plate or panel of porous construction material includes a movement structure that moves the plate or panel and includes at least one conveyor, and which is able to move in a direction (X). The device also includes a wire to cut the plate or panel and a structure for passing the wire in a direction (Y) perpendicular to the direction (X) of travel of the plate or panel. The device for cutting allows a cut to be made that greatly limits the waste and dust generated.