The ability of friction force microscopy to give insight into frictional processes on the molecular and atomic scale is exemplified by two different experiments. In the first example, friction force microscopy is employed on a GeS(001) sample covered with islands of epitaxially grown layers of C60 molecules. These measurements help analysing the nature of the dependence of the frictional force F f on the normal force F n . The markedly different frictional behavior on both materials results in a flip of the contrast in the acquired friction force maps with increasing F n . The second example focuses on triglycine sulfate (010) cleavage faces. Their asymmetric surface potential causes a highly direction-dependent frictional force when investigated with the friction force microscope. Both examples are discussed in detail and compared with the theory.