Kelvin probe force microscopy (KPFM), also known as surface potential microscopy, is one member of a suite of electrical characterization methods available in atomic force microscopes. It maps the contact potential difference between a surface and the cantilever, containing information about the surface potential and work function. KPFM is a surface-sensitive method that probes at and near the surface only. It is often used as a qualitative technique to obtain contrast based on the surface potential.