The quality of smooth technical surfaces is characterized by the surface roughness and by surface defects. For a stable quality control, objective measuring conditions are necessary. The objective measurement of surface defects especially is an unsolved problem. For the investigation of the scattering characteristics of different surface defects, a measuring device was developed. With this measuring device, the type of defect and the angle dependent scattering intensity were measured and compared with theoretical calculations.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.