An exposure method includes first through third steps. In the first step, respective first and second illumination regions of a mask having a predetermined pattern are illuminated with an illumination light having a predetermined wavelength. In the second step, an image of the mask is formed, respectively, in first and second exposure regions (formed on a substrate) based on the illumination that passes through the first and second illumination regions. The first and second exposure regions each have a substantially polygonal shape defined by two parallel sides and two sides other than the two parallel sides. In the third step, the first and second exposure regions and the substrate are moved relatively in a first direction such that the first and second exposure regions are formed in different positions in a second direction which crosses the first direction.