Abstract: An apparatus for measuring the distance to a workpiece, in particular a laser triangulation device is described. The apparatus includes a source of coherent radiation for illuminating the workpiece along an optical axis at a first angle relative to the surface of the workpiece, and an optical arrangement for detecting scattered light generated by the illumination, wherein the optical arrangement detects the scattered light at a second angle relative to the surface of the workpiece and wherein the second angle is different from the first angle. The optical arrangement includes detector that is spatially resolving it at least one dimension for the spatial resolved detection of the scattered light, and an interferometer comprising at least one moveably arranged mirror, which is disposed in the optical arrangement in such a way as to be in the path of at least a portion of the scattered light.