The semiconductor device manufacturing method comprises the step of transferring patterns formed on a reticle to a semiconductor substrate by an exposure with oblique incidence illumination. In the step of making the exposure with oblique incidence illumination, the exposure is made with an aperture stop 16 including a first ring-shaped aperture 22, and a plurality of second apertures 24a1-24a4 formed around the first ring-shaped aperture 22. The exposure is made with an aperture stop 16 having the first ring-shaped aperture 22 which can transfer patterns arranged at a medium pitch to a relatively large pitch with a relatively high resolution and the second aperture 24a1-24a4 which can transfer patterns arranged at a relatively small pitch with a relatively high resolution, whereby even when the patterns are arranged at various pitch values, the DOF can be surely sufficient, and the patterns can be stably transferred.