Oxygen permeable asymmetric membranes of Ca0.8Sr0.2-Ti0.7Fe0.3O3-delta were applied to a one-component membrane reactor (OCMR) for the partial oxidation of methane. CH4 conversion and oxygen flux of OCMR with a 43-mu m dense layer at 1173K reached 71% and 1.7 mL min(-1) cm(-2), respectively. These values are 2.5 times greater than that of a 500-mu m self-supported membrane.