To provide a common-path-type measuring system for measuring the three-dimensional shape of a specimen in noncontact with the specimen.

The measuring system (100A) is equipped with: a light source part 11 which emits a measuring beam (L1), and a reference beam (L2) with respect to the measuring beam; and a measuring optical system (12). The optical system (12) has: a flat-plate-like reference element (13) arranged adjacently to the specimen for reflecting the reference beam and transmitting the measuring beam to the specimen; a light-dispersing element (20) for dispersing an interference beam acquired by the interference between the measuring beam reflected by the specimen and the reference beam reflected by the reference element into each wavelength; a detection part (24) for detecting each wavelength dispersed by the light-dispersing element; and a bypass path having an optical path length of the measuring beam from the light source part to the detection part via the specimen and the light-dispersing element and an optical path length of the reference beam from the light source part to the detection part via the reference element and the light-dispersing element.