Abstract: A vacuum film deposition method comprises the steps of mounting a substrate on a substrate holder (6a) that is disposed in a vacuum chamber (1) and is provided with a passage (7f), (7g), and (7j) in which predetermined heat medium flows; maintaining an inside of the vacuum chamber substantially in vacuum state; evaporating evaporation materials from two or more evaporation sources in the inside of the vacuum chamber; and diffusing the evaporated evaporation materials in the inside of the vacuum chamber in a predetermined order; and depositing the diffused evaporation materials on a deposition surface of the substrate, thereby forming a multi-layered film made of the evaporation materials on the deposition surface of the substrate; wherein an antifreezing fluid is used as the predetermined heat medium flowing in the passage of the substrate holder.

Abstract: A first SiO film having a refractive index substantially equal to the refractive index of an acrylic resin substrate is formed to a thickness of about 200 nm on the substrate, and a second SiO film having a refractive index assuming a value falling within the range from 1.48 to 1.62 is formed to a thickness of about 200 nm on the first SiO film. Further, in the case of an HLHL type antireflection film for example, a TiO2 film having a refractive index assuming a value falling within the range from 2.2 to 2.4 is formed as the layer next to the outermost layer with a special ion plating apparatus.