Patent ID: 8233140

Claim:
A measuring apparatus which measures a shape of a surface of a measurement target object, comprising: a light projecting optical system configured to split light from a light source into measurement light and reference light so that the measurement light enters the surface of the measurement target object and the reference light enters a reference mirror; a light receiving optical system configured to guide the measurement light reflected by the surface of the measurement target object and the reference light reflected by the reference mirror to a photoelectric conversion device; and a processing unit configured to calculate the shape of the surface of the measurement target object based on an interference pattern which is detected by the photoelectric conversion device and formed by the measurement light and the reference light, wherein at least one of said light projecting optical system and said light receiving optical system includes an imaging optical system including a plurality of mirrors which include a concave surface mirror and a convex surface mirror, a magnification of said imaging optical system is determined by said plurality of mirrors, the convex surface mirror has a curvature twice a curvature of the concave surface mirror, and the concave surface mirror and the convex surface mirror are arranged such that the center of curvature of the concave surface mirror does not match the center of curvature of the convex surface mirror.