Auger electron spectroscopy (AES) and x-ray spectrometry are complementary: both are the result of a primary electron beam interacting inelastically with specimen atom core electrons. A core electron is ejected and as a higher level electron moves to fill the vacancy, the energy difference between these levels is released either with the ejection of another bound outer shell electron as an Auger electron with a characteristic kinetic energy or as a characteristic x-ray photon. Auger electrons and x-rays are produced throughout a sample volume defined by the beam energy and specimen composition, but the sampling depths are quite different. While x-rays can suffer absorption, those that escape retain their characteristic energy and therefore represent the entire range of generation, which may be micrometers. Because of the simultaneous nature of energy dispersive x-ray data collection, the entire spectrum can be collected at each pixel and post processed for composition. Auger electrons suffer inelastic scattering and so can only travel a small distance in the sample while retaining their characteristic energy. Only the Auger electrons that are created within a few nanometers of the surface have a sufficient mean free path to escape the specimen and be collected for analysis. Auger electrons are measured with a spectrometer that has a narrow energy bandpass and must be sequentially scanned to record the spectral energy range of interest. Auger spectroscopy provides elemental and chemical information because the atomic energy levels involved in Auger emission are also influenced by chemical bonding between atoms. The complementary nature of Auger and x-ray microanalysis with their different sampling depths can be exploited to view the composition of the bulk and the surface of a specimen.