Exposure apparatus and method of manufacturing device

An exposure apparatus including an illumination optical system which illuminates an original with light emitted by a light source, and a projection optical system which projects a pattern image of the original illuminated by the illumination optical system onto a substrate, the apparatus comprising:

• a light dividing surface which reflects a certain component of the light beam bifurcated by the illumination optical system, and transmits the remaining component of the light beam;
• a first photoelectric conversion element which detects the light beam transmitted through said light dividing surface;
• a second photoelectric conversion element which detects the light beam reflected by said light dividing surface;
• and
• a controller which controls the light beam which becomes incident on the substrate, using the outputs from said first photoelectric conversion element and said second photoelectric conversion element while the light emitted by the light source is in a first polarization state, and the outputs from said first photoelectric conversion element and said second photoelectric conversion element while the light emitted by the light source is in a second polarization state different from the first polarization state,
• wherein said light dividing surface is a surface, on a side of the illumination optical system, of a light beam dividing unit which divides the light beam bifurcated by the illumination optical system into transmitted light and reflected light,
• wherein said first photoelectric conversion element and said light beam dividing unit are integrated with each other,
• wherein said light beam dividing unit is held by said first photoelectric conversion element through a bump.