Patent ID: 8228509

Claim:
A shape measuring device comprising: light projecting means for projecting a light flux to a measurement portion, which is an end portion of a disc-shaped measurement target, from a direction parallel with each face of front and back sides of said measurement target and image pickup means for picking up a projection image of said measurement portion from a direction opposing the light projection direction, said light projecting means including: a point light source; a collimator lens for having outgoing light of said point light source pass and collimating the same in said light projection direction; and a single or a plurality of masks for shielding passage of a part of the light flux traveling from said collimator lens toward said measurement target side and shielding the passage of the light in a range outside image pickup, which is a range outside an outline of an image pickup range of said image pickup means seen from said light projection direction, wherein a shape of the end face of said measurement target is measured on the basis of said projection image obtained by said image pickup means, wherein said shape measuring device further comprises: center sucking and supporting means for supporting said measurement target by sucking a center part of one of faces thereof; and parallel supporting means for supporting one of the faces of said measurement target at a position on the center side with respect to said measurement portion in said measurement target supported by said center sucking and supporting means in parallel with said light projection direction.