Patent ID: 8226751

Claim:
A composite membrane material for hydrogen separation comprising: a hydrogen-permeable membrane which is selectively permeable to hydrogen and is formed by rolling to a thickness of 30 μm or less which is difficult for the membrane by itself to retain its shape, and a shape-retention mesh for retaining the shape of said hydrogen-permeable membrane, which is disposed on at least one side of said hydrogen-permeable membrane and which comprises a metal wire of a metal selected from high-melting metals which have a melting point higher than the melting point of said hydrogen-permeable membrane, wherein said hydrogen-permeable membrane and said shape-retention mesh are superimposed and subjected to a pleat processing to provide pleats continuously so that the S/So ratio is from 3 to 10 in which So is the area of a datum plane passing through the middle points in height of the pleats of said hydrogen-permeable membrane at the average height, and S is the surface area of the hydrogen-permeable membrane located within said datum plane.