To enable high-accuracy exposure.

Small regions 3(3a-3d) with warp measuring marks are provided at a pattern region 1a of a mark 1, the positions of these marks are measured to obtain a warp of the mask 1, and a pattern image projected on a wafer is corrected, based on the warp. If the mask to be exposed has any warp, a high-accuracy pattern exposure is possible. The small regions 3 may be disposed at the periphery of the pattern region 1a or mixed with small regions 2 over the entire pattern region 1a.