Abstract: The present invention relates to an apparatus for measuring the position of an object (30), comprising at least one laser interferometer system (29) for determining a position displacement of the object (30) in at least one spatial direction, wherein the at least one laser interferometer system (29), together with the object (30), are accommodated in a climate chamber (40) comprising an area (42) with air intake apertures and an area (44) with air exhaust apertures, wherein it is suggested to provide means for directing in operation at least part of the airflow (46) through the climate chamber (40) into the area of the laser axes (52, 54) of the at least one laser interferometer system (29).