The present invention provides a manufacturing method of semiconductor multilayer wiring boards featuring with the simplification of manufacturing processes and a reduction in manufacturing cost, by completely wetting all processes of: forming an insulating layer between low-dielectric constant silica-based layers on a substrate; forming a wiring forming space by a dual damascene method; forming a dense and thin diffusion-proof film on an organic monomolecular film in the space; and forming a wiring layer in the space. The method includes steps of forming a wiring-layer forming space in an insulating layer between low-dielectric constant silica-based layers that is formed on a substrate by using a spinning coating with a glass material; irradiating ultraviolet rays in an oxidizing atmosphere as the need arises to perform the treatment for bonding Si-OH on the surface of the insulating layer; next using a silane-based monomolecular layer film to adhere to the inner surface of the wiring-layer forming space by using an organic silane compound; catalyzing the monomolecular layer film with a palladium compound aqueous solution; forming a plated film with high copper diffusion-proof properties is formed on this catalyzed monomolecular layer film by electroless plating; and forming a plated copper layer and a wiring layer on this copper diffusion-proof film.