Abstract: The exposure device is especially intended for use with the contact print of circuit patterns on printed circuit boards, and is composed of a tubular light source extending with the length thereof throughout the exposure field width and disposed in a housing light-permeable over the exposure field, with the light source being disposed within a reflector open toward the exposure field and a light-directing grid covered by the side flanks of the reflector being located underneath the light source, and a heat insulating plate being provided underneath the light directing grid.