Abstract: A method of inspecting the surfaces of materials to be examined, wherein the surface is scanned line by line by an optical measurement pickup and the signal furnished by the measurement pickup is processed in order to obtain information about the consistency of the surface of the material to be examined, with the picked up lines each being processed in sections in that for each section the average, the maximum and/or the minimum values, as well as an intermediate value, which is representative of the respective section and which is used for further processing, are determined. If the maximum or minimum values lie outside of a given tolerance zone that extends around the average value, the intermediate value equals the maximum or minimum, respectively, otherwise it equals the average value.