To provide a mask capable which is adequately usable for measuring improving characteristics of a projection optical system.

First and third patterns (LS1 and LS3) including line patterns extending in a first direction and second and fourth patterns (LS2 and LS4) including line patterns extending in a second direction are formed on a pattern surface (PA) of a mask substrate (42) constituting the mask (RT). The first and second patterns and the third and fourth patterns which are formed to the same line widths make pairs, respectively. Accordingly, the exposure of the first time by which, for example, the respective patterns are transferred to the substrate and the exposure of the second time by which at least the one patterns are transferred in superposition on the transferred images of the patterns making a pair are carried out, by which the images of the rhombic marks having the same resolution at any of their peripheral edges are formed in the parts overlapping on each and therefore the various imaging characteristics of the projection optical system can be measured by measuring the prescribed lengths of the images.