The Auger electron spectrum induced by the impact of 100‐keV Ar+on metallic aluminum is shown to be consistent with the source of Auger electrons being ejected target particles. The principal spectral line has been identified as being due to ejected Al atoms with a single 2pvacancy. Subsidiary peaks are due to ejected atoms and Al+ions with one or two 2pvacancies. The ion‐induced Auger spectrum of silicon is similar. By contrast the spectrum induced by Ar+impact on Be exhibits a rather broad peak characteristic of aK‐shell vacancy and is similar to that induced by the impact of electrons. By considering the lifetime of the BeK‐shell vacancy we conclude that the Auger decay occurs while the Be atoms are either in the solid or interacting with the surface.