Abstract: An electrochemical autothermal reformer (EATR) provides hydrogen. The EATR includes an autothermal reformer region, a reformer anode supply region, and a composite membrane layer separating the reformer anode from the autothermal reformer region. The composite membrane layer includes a mechanically stable porous ceramic support member with a thin gas permeable ceramic substrate layer overlaying the support member. Overlaying the substrate layer is a first thin metallic catalyst layer which promotes the dissociation of H.sub.2 to 2H.sup.+ +2e.sup.-. Overlaying the first catalyst layer is a metallic oxide layer capable of conducting 2H.sup.+ +2e.sup.- at elevated temperatures. Overlaying the metallic oxide layer is a second thin metallic catalyst layer which promotes the recombination of 2H.sup.+ +2e.sup.- to H.sub.2.