In this contribution we report on the nanostructure and conductivity of freshly prepared as well as artificially degraded Nafion membranes investigated by contact atomic force microscopy (AFM),conductive AFM, and pulsed force-mode (PFM)-AFM. The different techniques can provide complementary information on structure and conductivity. Conductive AFM gives information about the internal structure of ionic clusters during current flow. High resolution current images of the membrane were used to directly compare the measured nanostructure of the single conductive channels with model predictions from the literature. The influence of H2O2 treatment as a method for artificial degradation is investigated. The analysis of adhesion forces demonstrates a significant change of thesurface properties with different membrane treatment. Topography and adhesion measurements clearly show materials changes with high resolution and correlate with changes in conductivity distributions.