We discuss recent progress in the investigation of photon emission processes occurring in the tip‐surface region of the STM. Through the use of selected examples recorded on metals and semiconductors some interesting aspects of this area of research are presented. In particular, radiative plasmon modes on metals specific to the STM geometry and their excitation by inelastic tunneling are compared to luminescence processes in semiconductors. The ability to fabricate nanostructures on Cu and investigate their photon emission characteristics with atomic resolution is included to give a feeling for the frontier aspect of this research.