In practice, two surfaces statically equivalent can be issued from two different manufacturing processes (grinding, belt finishing, honing, …) or obtained using different working process variables (abrasives grits size, contact pressure, …). The common tools and different norms used for industrial surface characterization (ISO 4288, ISO 12085, …) have the main limit of discriminating them through their process signatures. This Note introduces a multiscale decomposition method of the surface topography based on continuous wavelets transform. This approach allows the determination of the multi-scale transfer function of the morphological modification on the surface topography after a finishing process. This technique has been successfully applied to discriminate two surfaces obtained by the belt-finishing process. Moreover, it makes it possible to connect the surface topography modification to the physical and tribological mechanisms of the process (ploughing, cutting, …). To cite this article: S. Mezghani et al., C. R. Mecanique 336 (2008).