Exoelectrons are emitted from solid surfaces stimulated with light illumination (OSEE, PSEE) or heating (TSEE) after prior damage externally introduced by mechanical treatment or exposure to ionizing radiation. The emission of low-energy electrons is detected by employing a GM counter, electron multiplier or picoammeter. Exoelectron emission (EE) is a complicated phenomenon composed of various physical and chemical processes. Despite uncertainty in the mechanism, EE has been applied successfully in the study of radiation dosimetry, metal deformation and fatigue, and other surface phenomena. Fatigue failure of metals can be predicted by measuring the total emission of PSEE from surfaces, or from the change in intensity of the largest PSEE peak during the fatigue cycle. The EE microscope has proven to be a useful tool for the examination of metal surfaces associated with the generation and extinction of a fresh surface.