An interferometer includes a light source, beam splitter, measuring reflector, reference retroreflector, detector system, and two transparent plane plates. The beam splitter splits a first beam of rays, emitted by the light source, into at least one measuring beam and at least one reference beam, defining a first splitting plane. The measuring beam propagates in a measuring arm and the reference beam propagates in a reference arm until being recombined at a recombining location, which is oriented parallel to the first splitting plane. The measuring reflector is disposed in the measuring arm, and the reference retroreflector is disposed in the reference arm. The first and second transparent plane plates are disposed parallel to each other in the beam path between the light source and the detector system. The reference retroreflector is formed in the first plane plate and the beam splitter is disposed on the second plane plate.