Abstract: A metal-film forming method of the present invention includes a surface activation process of irradiating a laser beam to the surface of the base metal, thereby activating the surface of the basemetal, a noble-metal nanoparticle dispersion liquid coating process of coating the surface of the base metal with a noble-metal nanoparticle dispersion liquid, a solvent thereof, containing noble-metal nanoparticles in as-dispersed state, and a noble-metal nanoparticle sintering process of irradiating the laser beam to the noble-metal nanoparticle dispersion liquid coated on the surface of the base metal, thereby causing the noble-metal nanoparticles to be sintered. Further, a scudding press process of executing press forming of a base metal, and the metal-film forming process of applying noble-metal plating to the surface of the base metal are executed on the same line.