To reduce the cost without wasting the catalyst metal, and to evenly disperse for carrying the catalyst metal in a catalyst bed.

A porous catalyst bed, which includes the conductive powder and to which the water repellent finishing is not performed, is formed on the surface of a porous conductive base material sheet, which includes the conductive component and the water repellent agent and to which the water repellent finishing is performed, so as to form a conductive sheet, and this conductive sheet is dipped in the bath of the catalyst metal solution. The catalyst metal solution is not permeated through the conductive base material sheet, to which the water repellent finishing is performed, and evenly permeated through the only catalyst bed, to which the water repellent finishing is not performed. The conductive sheet, which is pulled up from the bath, is vertically held for drying, and after heating is performed to the conductive sheet, the conductive sheet is turned and dipped in the bath again, and this process is repeated so that the catalyst metal is evenly carried in the catalyst bed.