Abstract In this application note, the experimental setup for KFM and CSAFM imaging under controlled humidity using an Agilent 5500 AFM system is illustrated. The results from the study of a proton exchange membrane using KFM and CSAFM under controlled humidity are presented. These results demonstrate that KFM and CSAFM are powerful tools for studying the surface properties and the ionic conductivity of proton exchange membranes used in fuel cell technology.