It is well known that the adhesive strength of thermally sprayed coatings is greatly influenced by the roughness or topography of the roughened substrate conventionally obtained by grit blasting. As it is important in the thermal spray industry to obtain and control high adhesive bond strength, it is essential to understand how the roughness affects the strength between the coatings and the substrate, and the particle interaction process with the substrate. To clarify the bonding aspect, this paper proposes a characterizing method of the substrate surface roughness or topography, under the hypothesis that the mechanical friction between the coating and the substrate primarily influences the adhesive strength. A confocal scanning microscope is used to measure three-dimensional surface profiles, and a computing program is developed for calculation of the numerical data measured with the microscope. Paper includes a German-language abstract.