The chemical stability of La0.6Ca0.4CoO3 perovskite as an electrocatalyst in bifunctional oxygen electrodes has been studied by ex-situ and in-situ X-ray absorption spectroscopy and X-ray diffraction measurements. The catalyst was investigated ex-situ as a powder mixed with BN, and in-situ on carbon supports in bilayer air electrodes at different potentials in an electrochemical cell with an alkaline electrolyte. It was found to be stable for at least 1300 h in electrodes operated under the conditions of rechargeable Zn/air cells.