US Patent 7098991 Exposure method, exposure apparatus, and method for manufacturing device

According to one embodiment of the invention, a pattern of a mask is transferred onto a substrate via a projection optical system using an energy beam by placing a substrate on side of an energy beam emitting end portion of projection optical system, when the substrate is exposed, and placing an object on the side of the energy beam emitting end portion of the projection optical system in place of the substrate when the substrate is exchanged. This can adequately remove a light absorptive substance from the region near an output end of the projection optical system and can maintain the gas state even at a time of moving or replacing the substrate.