The invention relates to a metal multi-layered film structure, comprising two types of metal films including first metal films and second metal films alternately formed on a resin substrate. The first metal films are composed of an aluminum-based material having a film thickness between 0.7 nm and 20 nm. The second metal films are composed of one selected from the group consisting of stainless steel-based materials, nickel-based materials, cobalt-based materials, titanium-based materials and chromium-based materials, having a film thickness ranging from 1 nm to 20 nm. This metal multi-layered film structure can be manufactured through a method of sputtering. The metal multi-layered film structure is suitable for an extension reflector for vehicular lamps.