Abstract: A displacement interferometer system comprises: a light source for generating a laser beam of a predetermined wavelength; an incidence unit for allowing the laser beam, generated in the light source to be incident on a target object to be measured; a detector for measuring a distance of the target object to be measured, using a measurement laser beam which is incident on the target object by the incidence unit; and a correction unit connected to the incidence unit so that a correction laser beam is incident in a direction parallel to the measurement laser beam which is incident on the target object to be measured. When the correction laser beam and the measurement laser beam which yaw from an initially set direction are incident in any one direction, the correction unit corrects the correction laser beam and the measurement laser beam to be incident in the initially set direction.

Abstract: There are provided a displacement interferometer system which increases or maximizes productivity, and an exposer using the same.