A biaxially oriented polyester film to be molded and laminated with a metal sheet which shows excellent moldability when it is laminated with a metal sheet and subjected to a can making process such as drawing and from which a metal can such as a drink can or food can having excellent heat resistance, retort resistance, taste and odor retention properties, impact resistance and corrosion preventing properties can be produced. This polyester film is produced from a copolyester which contains porous particles having an average particle diameter of 0.1 to 2.5 &mgr;m, a pore volume of 0.05 to 2.5 ml/g, a specific surface area of 50 to 600 m2/g and a compressive resistance of 1 to 100 MPa and has a glass transition temperature of 70° C. or higher and lower than 78° C., a melting point of 210 to 250° C. and an intrinsic viscosity of 0.50 to 0.80 dl/g.