To eliminate influence of undesirable light component from an object when measuring optical characteristics such as shape and wavefront aberration of the object, light from light source (101) is separated by polarization beam splitter (103) into measuring light (L1) that irradiates and travels via the object (108) and is condensed on image plane (P) through microlenses (114a) of microlens array (114), and reference light (L2) that does not irradiate the object and is guided to the image plane by reference light optical system (109). A computer (113) acquires picked-up images sequentially from CCD image sensor (116) arranged on the image plane while changing optical path length of the reference light by movable stage (117), extracts interference light spots generated through interference between signal light component and the reference light from the picked-up images, calculates positions of the interference light spots, and calculates deviation amounts of positions from predetermined reference positions.