A reflecting film has at least a transparent polymer film and a thin silver layer applied on the transparent polymer film to reflect light entered from a side of the transparent polymer film. The reflecting film retains a reflectance of at least 90% to visible light even after the reflector is exposed for 300 hours at a reflecting film temperature of 100.degree. C. and an exposure intensity of 500 mW/cm.sup.2 to artificial sunlight from which light of 390 nm and shorter in wavelength has been eliminated. For fabricating the reflecting film, a surface of the transparent polymer film is preferably treated with a metal-containing plasma, then the thin-silver layer is deposited on the treated surface. A reflector making use of the reflecting film is also disclosed.