To eliminate an influence by the distortion of a lens and to improve alignment accuracy by arranging an alignment mark on a mask at a position where the distortion of the lens is not found.

The alignment marks A to D arranged at the position where the distortion on the projection lens of an aligner is not found, for example, the center of the lens are used, and formed on a substrate 1. Thus, an error caused by the distortion is not included in the positions of the marks A to D formed on the substrate 1. Therefore, the alignment accuracy is improved by superposing layers when and after the positions of the marks A to D are read. Since a distortion component ordinarily included by about 0.5 μm is removed, the alignment accuracy is improved and yield is improved.