Abstract: In addition to triangulation methods, measurement systems according to the confocal principle are employed for the three-dimensional sensing of surfaces. These measurement systems have a higher resolution but, under certain circumstances, a lower data rate. An optical proximity sensor is described which, on the basis of the confocal microscope, carries out automatic inspection of surfaces in a time which is acceptable for a fabrication process. A linear system of corresponding light sources and photo receivers is used instead of a scanning beam, which requires a high outlay for generation. The optical path length between the receiving unit and the optical imaging arrangement is varied for the resolution of height values, wherein a light intensity maximum is detected by a peak detector.