[en] Auger electron spectroscopy (A.E.S.) allows to characterize the atoms lying at surfaces of amorphous and crystalline materials and to investigate their chemical bond. In the case of single crystals it is generally associated with LEED which gives information on the surface structure. After having recalled some principles about radiationless deexcitation of atoms and the related Auger transitions, the problems of interpretation of energy spectra in the case of a single atom and their of an atom bound to neighbours either of the same kind or of a different one, are discussed. Some applications of A.E.S. as an analytical method are finally described