Membrane reactors for selective oxidation of methane to higher hydrocarbons were designed and successively operated. In this system, methane was converted by oxide ion supplied through the non-porous membrane film. Three types of membrane reactors were developed for the oxidative coupling of methane. The first one consists of a porous tube covered with a thin film of catalyst oxide (Type-I), the second one is a non-porous tube of solid ion conductor covered with a catalyst layer (Type-II) , and the third one is a non-porous tube made of perovskite-type mixed conductor which itself has activity for methane conversion (Type-III). Type-I and II membranes converted methane to C2 hydrocarbons with the selectivity higher than 90%.