The polarization resistance of various electrode materials on stabilized zirconia has been measured, using impedance spectroscopy, at oxygen pressures ranging from 1 to 100 bar. Two metallic deposits have been tested: a metal dissolving no oxygen, i.e. platinum, and a metal dissolving high oxygen content, i.e. silver. The results are interpreted in terms of oxide formation. The behavior of an oxide with perovskite structure (doped lanthanum manganite) is interpreted by a change of the stoichiometric ratio at high oxygen pressure.