Data are presented which show how the adsorption of carbon monoxide and oxygen on atomically clean germanium affect the process of Auger neutralization of He+and Ne+at the surface. Measurements of both total yield and kinetic‐energy distribution of ejected Auger electrons have been made. The effect of ion bombardment alone without subsequent anneal, including the presence of absorbed noble gas in the surface layers of the crystal, has been investigated. Photomicrographs of the germanium target surface are reproduced.