An exposing method that forms a pattern of a reticle on a wafer is provided. In the method, part of the pattern of the reticle in an illumination area, which is illuminated by illumination light from an illumination optical system, is illuminated, and while scanning the illumination area with respect to the reticle in the +Y direction (or the −Y direction) by pivoting a deflection mirror, the reticle is moved in the corresponding −Y direction (or the +Y direction) and the wafer is moved in a direction that corresponds to the movement direction of the reticle.