The effect of argon etching on alpha- and gamma -alumina surfaces as well as at Pt/alumina interfaces has been studied by electron-induced X-ray emission spectroscopy. After etching, the superficial zones of both alumina present similar Al 3p spectral densities, showing that the environment around the Al atoms is similar. This effect is limited to the first 10 nm because of the energy of the argon ions. The Al 3p valence states observed at the Pt/alumina interfaces are similar for both substrates. This is in agreement with adhesion force measurements, which do not show variation of adhesion between the two kinds of samples. It is suggested that the metal/ceramic adhesion observed in these conditions is due to an interaction between the Al and Pt valence states.