Dicing lines extending longitudinally and transversely, and chip areas surrounded by the dicing lines are formed in a resist mask. Critical-dimension patterns are formed in the dicing lines so as to be paired while placing the center line thereof in between. The dimensional measurement of the resist film having these patterns formed therein is made under a CD-SEM, by specifying a measurement-target chip area out of a plurality of chip areas, and by specifying a position of a critical-dimension pattern on the left thereof. Then, the distance of two linear portions configuring the critical-dimension pattern is measured, wherein a portion at a point of measurement on the measurement-target chip area side as viewed from the center line of the dicing line is measured.