What is provided is a method and an apparatus for easily forming a multilayer structure of conductive metal thin films while forming a metal oxide thin film regardless of the conductivity of a substrate. A thin film of conductive metal is laminated by: dissolving metal precursors for a metal oxide to be formed and an oxidant to oxidize the metal precursors in a supercritical fluid or subcritical fluid; forming a metal oxide thin film by an oxidation reaction on the surface of a substrate in the supercritical fluid or subcritical fluid; then, dissolving a reducing agent and conductive metal precursors in a supercritical fluid or subcritical fluid; while reducing the metal oxide thin film formed on the surface of the substrate to a metal thin film, reducing the conductive metal precursors on the reduced metal thin film.