The cathode 114 is formed by forming several layers comprising an inorganic material that is primarily electron conductive and a complex oxide B that is primarily oxygen ion conductive and that supports an oxygen dissociation-promoting catalyst, on an electrolytic membrane 112. The electrolytic membrane 112 and the outermost layer of the cathode 114 (layer of mixture furthest from the electrolytic membrane 112) facing the separator 120 are physically and electrically continuous by means of the inorganic material a and complex oxide B disposed between them.