As a method for forming a fine wiring by electroless plating, for example, Patent Literature 1 discloses a method where a resin base surface with excimer light in a desired pattern, the resin base is then brought into contact with a silane coupling agent having an amino group or an amino-modified reactive silicon oil, a receptive layer for trapping/immobilizing a catalyst for initiating an electroless plating reaction is formed on the part irradiated with the excimer light, and a nickel/phosphorus plating layer is formed on the receptive layer by electroless plating.