Interferometric shape measurement of different signs of curvature

摘要

A measurement method of the present invention is a measurement method for measuring a shape of a target T from an interference pattern generated by interference between a reflected light of the target and a reference spherical surface. The measurement method includes a first measurement step which positions the target T in a first region 30a at a light source side with respect to a focal position 20 of the reference spherical surface to measure the interference pattern, and a second measurement step which positions the target T in a second region 30b opposite to the first region with respect to the focal position 20 of the reference spherical surface to measure the interference pattern.