| abstract |
In the preliminary film formation of an optical film for forming a multilayer optical thin film on a film substrate, by simultaneously energizing a plurality of sputtering chambers, a laminate of a thin film of two or more different materials is formed on the film substrate, and formed in a sputtering device From the optical properties obtained by the optical measurement unit 80, the film thicknesses of the plurality of thin films are calculated. The measurement of the film thickness and the adjustment of the film formation conditions of the thin film are repeatedly performed until the optical characteristics obtained by the optical measurement unit or the film thicknesses of the plurality of thin films calculated from the optical characteristics are within a predetermined range. |