To obtain a measuring method in which the accuracy of a measured value for every measuring point is increased and in which the distortion of a lens can be measured in a short time by a method, wherein the exposure of a pattern, for measurement which is stepped and moved is executed in the number of several times in the same point and an image distortion generated in a projection optical system in a measured value based on plural exposures measured.

A measuring pattern which is formed by a resist 12 in a measuring point is a box mark 13. For example, an inside pattern part is exposed by a field whole-face exposure operation, and an outside pattern part is exposed by a stepping exposure operation. The box mark 13 is formed in such a way, that its exposure is performed several number of times at several fractions of an exposure amount. The outside pattern part is formed of a plurality of resist latent images corresponding to a stepping exposure operation for each time. When the latent images are developed, one resist pattern is formed. The patent images which are average and from which the effects of distortion is removed are formed on a resist layer by the plural number of times for the exposure operation. The box mark 13 by the resist pattern from which a distortion is removed after their developing operation is formed.