The invention is a lithographic projection apparatus that comprises a radiation system which can form a projection beam of radiation, from radiation emitted by a radiation source, as well as a support structure constructed to hold patterning means, which when irradiated by the projection beam provides the projection beam with a pattern, a substrate table constructed to hold a substrate, and a projection system constructed and arranged to image an irradiated portion of the patterning means onto a target portion of the substrate. The radiation system further comprises an aperture at a distance from the optical axis, a reflector which is placed behind the aperture when seen from the source and a structure placed in a low radiation intensive region behind the aperture.