SILVER ALLOY STACKED FILM, OPTICAL REFLECTOR, OPTICAL INFORMATION RECORDING MEDIUM, FLAT PANEL DI

PROBLEM TO BE SOLVED : To provide a metal film having high reflectance and excellent durability (chemical stability and thermal resistance), and to provide an optical reflector using such excellent characteristics. SOLUTION : The following stacked films and its product are provided : (1) a Ag alloy stacked film which is constituted so that at least one kind of Ag alloy stacked film is formed on a substrate and a pure Ag film is formed thereon and in which the Ag alloy film on the substrate side has higher thermal resistance than the pure Ag film on the upper layer; (2) a Ag alloy stacked film which is constituted by successively stacking at least two kinds of Ag alloy films on the substrate and in which the Ag alloy film on the substrate side has higher thermal resistance than the Ag alloy film on the upper layer; (3) a Ag alloy stacked film which is constituted so that the Ag alloy film on the substrate side contains one or more rare earth elements by 0.1 to 3.0 atom% in total in the above Ag alloy stacked films; (4) an optical reflector which is manufactured by forming one of the above Ag alloy stacked films on the substrate.