The utilization of a fuel cell-powered electric vehicle and a distributed-type power generation system using fuel cells have been strongly expected from the viewpoints of sustainable energy system, environmental problems and energy security. For the realization of them, highly efficient and economically reasonable hydrogen production processes will be necessary. Ideally, hydrogen should be produced from renewable energy sources; however, a substantial amount of hydrogen will continue to be produced via the steam reforming or the partial oxidation of fossil fuels in near- to medium-term future. The membrane reformer that incorporates a hydrogen-permeable membrane into catalytic reformer will be hoped as one of the highly efficient hydrogen production processes. In this presentation, our challenges for fundamental study on a membrane reformer using various fuels as well as fabrication of a dense and thin palladium-based membrane by compositing to an inorganic porous support will be introduced. Recent topics are the fabrication of palladium alloy membrane by electroplating with the existence of supercritical carbon dioxide, and the diversification of the fuel applicable to the membrane reactor.