The thermally processed silver (TPS) film used in this study is a special type, which remains photoinsensitive until subjected to preliminary heat treatment. Various metal ions were investigated to improve the shelf life of the TPS film. Co (III) acetylacetonate was as effective as Hg (II) acetate in keeping the raw TPS film both under light illuminated condition and under thermally accelerated condition. The cooperative mechanism with catalyst for oxidation such as Co ion and oxidizing agents such as iodine molecules which had previously been proposed was further supported by the result of this study. The TPS films containing acetylacetonates of Co (II), Ni (II), Ce (III) and Cr (III) showed improvement only in heat stability of raw films, but no improvement in light stability. Actylacetonates of other metallic species such as Fe (II), Fe (III), Cu (II) and Mn (III), inversely, reduced the stability of the raw TPS films. For the present, we cannot theoretically explain the order of metallic species to affect the stability of the raw TPS films.