Tip-enhanced Raman mapping (TERM) can be used to obtain chemical analysis of a sample with a topographical resolution down to 15¿nm. A short review of this technique is given. Among other samples (e.g. carbon nanotubes and graphene), we recently measured a high resolution tip-enhanced Raman map of a polymer for the first time. Using TERM, the phase separation behaviour of a polymer blend (PMMA/SAN) was monitored. In the early, incomplete state of phase separation an interface width of ~200¿nm was measured. A spatial resolution in the tens of nm range could be achieved.