A method of forming a pattern for a semiconductor device comprises the steps of forming a photosensitive film on a substrate and radiating the photosensitive film on the substrate with a beam of a predetermined shape consisting of one of a charged particle beam and an electromagnetic beam, thereby forming an exposed region of a desired shape, the latter step including the step of exposing each of unit regions by a single shot of the beam of the predetermined shape for a predetermined period of time, repeating the exposure a plurality of times, and butt-joining the exposed unit regions to thereby form the exposed region of the desired shape, wherein, in the step of forming the exposed region of the desired shape, butting portions of the unit regions are situated in a first area of a layer to be formed other than a second area in the layer in which predetermined characteristics of a function of the semiconductor device are determined by a pattern width of the exposed region in association with another pattern formed in another layer.