The STM (Scanning Tunneling Microscope) provides a new tool for the investigation of the structure of metallic disordered systems on a near atomic scale in direct space. It is thus possible to simultaneously record the topography and the local tunneling barrier height (which yields a chemical analysis in terms of work function). Finally, the STM can be used in the spectroscopic mode well known from oxide barrier tunneling. The examples of glassy Rh-Zr and Pd-Si are discussed. Furthermore, the potential of this technique for the investigation of rapidly quenched nanocrystalline alloys such as FeNdB is presented.