In the case where the previous process (X) and the previous process (Y) are different in step 310, only a distortion amount in an X-axis direction is extracted from image distortion data of the previous process (X) in Step 316 and only a distortion amount in a Y-axis direction is extracted from image distortion data of the previous process (Y) in Step 318, and then in Step 320, image distortion data is created by synthesizing the extracted distortion amounts, and the synthesized image distortion data is used for subsequent adjustment of projected images. With this operation, the distortion of projected images can be adjusted per axis and accordingly overlay exposure with high accuracy can be realized.