The tracer gases exchange techniques were applied to the high temperature electrochemical ceramic devices to analyze the solubility of proton, diffusion of oxygen, and dynamics of oxygen reduction at ceramic interfaces. The secondary ion mass spectrometry (SIMS) analysis was conducted with quenched samples. The proton concentration in CeO2 based oxides was determined by D2O saturation. The estimated concentration of proton was from 10(-3) to 10(-2) mol per 1 mol oxide. Oxygen incorporation active points were visualized by scanning images of SIMS at the mesh-electrode/electrolyte interfaces. The SIMS scanning images clearly indicated that the O-2/electrode/electrolyte interfaces were most active points for oxygen incorporation. (C) 2002 Elsevier Science B.V. All rights reserved.