NOVELTY - An aluminum plastic film has a protective layer, a chemical treatment layer (c1), an intermediate foil, a chemical treatment layer (c2) and a heat sealing layer. The protective layer is obtained by cast-co-extrusion of polyamide-and-maleic anhydride-modified polypropylene or maleic anhydride-modified polyethylene. The chemical treatment layers (c1,c2) are obtained by chemically-treating using mixed solution of chromium salt, acid solution and fluoride.    USE - Aluminum plastic film is used for core of lithium-ion battery.    ADVANTAGE - The aluminum plastic film having high voltage characteristics, and excellent heat-sealing property and corrosion resistance is economically manufactured, by simple method.    DETAILED DESCRIPTION - An aluminum plastic film has a protective layer, a chemical treatment layer (c1), an intermediate foil, a chemical treatment layer (c2) and a heat sealing layer. The protective layer is obtained by cast-co-extrusion of polyamide-and-maleic anhydride-modified polypropylene or maleic anhydride-modified polyethylene and having amount of polyamide of 50-70 wt.%. The protective layer has thickness of 15-30 mu m. The chemical treatment layers (c1,c2) are obtained by chemically-treating using mixed solution of chromium salt, acid solution and fluoride, and have thickness of 0.2-1.2 mu m. The chromium salt is potassium dichromate, chromium oxide and/or sodium dichromate. The concentration of chromium salt in mixed solution is 0.2-1.2 %mass. The acid is hydrochloric acid, sulfuric acid and/or phosphoric acid. The concentration of acid in mixed solution is 3-15 %mass. The fluoride is ammonium fluoride, potassium fluoride and/or sodium fluoride. The concentration of fluoride in mixed solution is 0.1-1 %mass. The thickness of aluminum foil intermediate is 30-100 mu m. The heat sealing layer is obtained by cast-co-extrusion of maleic anhydride modified polypropylene or maleic anhydride modified polyethylene and polypropylene or polyethylene. The total content of maleic anhydride, and polyethylene or polypropylene is 20-60 %mass. The heat sealing layer has thickness of 20-100 mu m. The protective layer, aluminum foil and heat sealing layer are formed by thermal adhesion machine. The aluminum foil intermediate is preheated at 190-210 degrees C, the protective layer and heat sealing layer are attached to treated surface of aluminum foil intermediate using pressure roller. Complex thermal paste is coated and processed in hot oven and rewound, to obtain aluminum plastic film.