To provide a method and device for exposure, which enables exposure of good resolution mask patterns which are intermixture of L and S patterns, and isolated and complicated patterns, with fine line breadth (of not more than 0.15 μm, for instance), without changing mask.

A phase shift mask having a phase value of three or more is formed with a desired pattern and a dummy pattern of periodicity which is superposed on the desired pattern. The phase shift mask is lit up utilizing lighting that has a peak in the vicinity of optical axis and lighting that has a peak outside the optical axis. The light that has passed through the phase shift mask is projected to a surface to be exposed by way of a projection optical system, whereby the desired pattern is transferred to the surface to be exposed.