Peaks in the differential energy distribution resulting from losses of the type (Ep−E1), whereEpis the primary energy andE1is the critical ionization potential of an inner atomic shell giving rise to a strong Auger transition, have been observed during Auger emission spectroscopy. In the example presented, characteristic loss peaks due to ionization of the boron and carbonKshells are shown. Loss peaks are usually of the same order of magnitude as some of the smaller Auger peaks, and care should be taken in identification, under certain conditions of analysis, that the two are not confused.