Electrolyte composite member, and electrolyte/electrode composite member

PROBLEM TO BE SOLVED: To provide an electrolyte composite member and an electrolyte/electrode composite member which enable the reduction in resistance against ion conduction and which are superior in strength.SOLUTION: An electrolyte composite member comprises: a solid electrolyte layer including a metal oxide; and a porous body layer composed of a three dimensional mesh-like porous body formed from a metal oxide on at least one face of the solid electrolyte layer. The solid electrolyte layer and the porous body are integrally formed. The porous body has an average pore diameter of 1-2 mm, and a porosity of 90-97%. The solid electrolyte layer has an average thickness of 300 μm or less. The electrolyte composite member is utilized for a fuel battery.SELECTED DRAWING: Figure 1