An exposure apparatus including an illumination optical system to illuminate an original with exposure light of plural wavelengths, a projection optical system to project an image of a pattern of the original onto a substrate, an original-side reference pattern provided at an original side of the projection optical system, a substrate-side reference pattern provided at a substrate side of the projection optical system, and an image plane detecting system configured so that the original-side reference pattern is illuminated with the exposure light or light equivalent to the exposure light with respect to a wavelength component rate.