Patent ID: 7399423

Claim:
A production method of a hydrogen production filer filter using a thin film support substrate, comprising a disposing step of disposing an insulating film on a surface of the thin film support substrate where columnar convex portions are formed, so as to fix said insulating film to top surfaces of said columnar convex portions, said thin film support substrate comprising a metal substrate, the plurality of columnar convex portions formed on one surface of said metal substrate, and a plurality of through holes formed at a portion where said columnar convex portions are not formed, so as to pierce said metal substrate, wherein an area of the columnar convex portion non-formed portion occupying on the columnar convex portion formed side is within the range of 20 to 90%, an underlayer forming step of forming a conductive underlayer by electroless plating on said thin film support substrate excluding the top surfaces of said columnar convex portions and on a fixation side of said insulating film, a copper plating step of forming a copper plating layer on said conductive underlayer so as to fill up a space formed between the metal substrate of said thin film support substrate and said insulating film, and the inside of the through holes of said thin film support substrate, a film forming step of forming a Pd alloy film by plating on a surface formed by the top surfaces of said columnar convex portions and said copper plating layer after removal of said insulating film, and a removal step of removing said copper plating layer by selective etching.