US Patent 7595862 Exposure apparatus and method of manufacturing device

An exposure apparatus includes a light source; an illumination optical system that illuminates an original with the light; a substrate stage that holds and moves a substrate; a projection optical system that projects the light from the original, the projection optical system and the substrate having therebetween a first gap filled with liquid for exposure of the substrate; a first detector that detects a light quantity of light and passing along a light path of the illumination optical system; a second detector disposed on the substrate stage, to detect a light quantity of light transmitted through the illumination optical system and the projection optical system; and a calculator that determines a first conversion factor with respect to each of the plurality of exposure conditions used for conversion between a light quantity detected by the second detector with gas and a light quantity detected by the second detector with the liquid.