Auger electron spectroscopy (AES) is widely recognized as a method of determining the surface layer chemical composition. However, AES has some less widely known applications. Some of them are presented and discussed. The concentration depth profile can be determined with a resolution in the range of one monolayer with the use of the dependence of Anger signals of the sample components on the emission angle or the incidence angle of the primary beam. During the layer-by-layer growth of ultrathin films the Anger signal from the substrate and adsorbate decreases and increases, respectively, with the coverage increase. The dependences of those signals on the coverage consist of linear parts with smaller and smaller slopes corresponding to the formation of succeeding adsorbate monolayers. However, a similar picture is Obtained when, for example, the second monolayer starts to grow before the first layer is completed. This situation can be differentiated from the layer-by-layer growth by fitting the observed slopes mentioned above to the slopes calculated for particular growth modes. For crystalline samples, the Auger signal depends on the direction of the primary electron beam owing to its forward focusing and channeling. The signal becomes maximum when the direction is parallel to one of the close-packed rows of atoms in the sample. In the directional Auger electron spectroscopy (DAES) method, it is possible to deduce the symmetry and orientation of the crystalline structure from positions of such maxima.