An Ag-based reflection film consists of a laminate film comprising an Ag or Ag-
alloy film provided thereon with a quite thin capping layer. The Ag-based reflection film can be prepared by, for instance, forming, on a substrate, an Ag or Ag-
alloy film according to the
sputtering technique, while using a
sputtering target, for instance, having a composition corresponding to that of the pure Ag film, and Ar gas as a
sputtering gas, while adding an additional gas such as O2, only at the initial stage of the Ag or Ag-
alloy film-forming step; and then forming a quite thin capping layer, on the Ag or Ag-alloy film, according to the sputtering technique, while using a sputtering target having a composition corresponding to that of the capping layer, and Ar gas as a sputtering gas, while if necessary adding an additional gas such as O2. The Ag-based reflection film can maintain a high reflectance without causing any deterioration thereof even under the severe conditions such as those for the
hydrogen sulfide-
exposure test because of the presence of a quite thin capping layer. The reflection film may be applied to, for instance, those used for display devices and
optics-relating ones.