A friction pump (molecular pump, turbomolecular pump) has pumping surfaces which include surface areas which face upstream as well as surface areas which face downstream with respect to the pumping direction. In at least a portion of the pumping surfaces, surface areas of different roughness are present, such that the roughness of the surface areas facing downstream with respect to the pumping direction is greater than the roughness of the surface areas facing upstream with respect to the pumping direction.
