The Auger electron appearance potential spectra (AEAPS) of M 4,5 levels of lanthanum in the elemental state and in LaH 3 are presented. AEAPS measures the total differential secondary electron yield from the surface constituents as a function of incident electron energy. In the presence of a 3 d hole, the 4 f level is pulled down below the Fermi energy, E F. In the metallic La spectrum this is seen as a shoulder on the low energy side of the main peak, but in the LaH 3 spectrum this shoulder disappears and is replaced by two peaks, again on the low energy side. The high binding energy satellite reported in the M 5 level XPS spectra in La insulating compounds has been attributed to the lowering of the 4 f level above the ligand band. Since no high binding energy satellite is observed in the M 4,5 level AEAPS of LaH 3, the lowest energy peak is assigned as the transition of the 3 d electron to the 4 f level pulled down below the hydrogen induced band. The other peak is related to the partially filled hydrogen induced band below E F. Tentative energy level diagrams for these transitions are proposed.