To develop new chemical-energy conversion and storage systems using metal oxides, the kinetics of iron oxide (Fe2O3) reduction by humidified methane using an oxide ion conductor, CaTi1-xFexO3-delta (CTFO), as a support was analyzed. Significant improvements in Fe2O3 reduction rate and lattice oxygen utilization were observed using CTFO, which may be induced by rapid ion transport at the interface between Fe2O3 and CTFO.