A laminated film, comprising a polyester substrate film, and a coating layer on/over at least one surface of the polyester substrate film; the coating layer comprising a resin composition for coating layer, comprising, as a constituent component, a resin having an oxazoline group; the laminated film having an inorganic thin-film layer on/over the coating layer, and further having a protective layer that has a urethane resin and has an adhesion amount of 0.15 to 0.60 g/m 2 on/over the inorganic thin-film layer; the laminated film showing a total reflection infrared absorption spectrum having a ratio P1/P2 ranging from 1.5 to 3.5 wherein P1 is an intensity of a peak having an absorption maximum in a range of 1530 ± 10 cm -1, and P2 is an intensity of a peak having an absorption maximum in a range of 1410 ± 10 cm -1; and further the laminated film having an oxygen permeability of 3 ml/m 2 ·d·MPa or less under conditions of a temperature of 23°C and a relative humidity of 65%; wherein the urethane resin comprised in the protective layer comprises a m-xylylene component; wherein the total proportion of the aromatic or aromatic-aliphatic diisocyanate in the polyisocyanate component of the urethane resin is from 60 to 100 mol%; wherein the oxazoline-group-containing resin in the resin composition for coating layer contains an oxazoline group amount of 5.1 to 9.0 mmol/g; and wherein the adhesion amount of the protective layer, the oxygen permeability and the oxazoline group amount are measured according to the methods in the description; with the proviso that the laminated film is not a laminate film comprising a coating layer, a metal oxide layer and a protective layer, with another intervening layer or without any intervening layer, laminated in this order on at least one surface of a polyester substrate film, wherein the coating layer comprises an oxazoline group-containing resin and a polyurethane resin, wherein the metal oxide layer comprises a composite oxide composed of silicon oxide and aluminum oxide, and wherein the protective layer comprises a polyurethane resin, the polyurethane resin contains a metaxylylene group in an amount of 20 to 33% by mass and a silanol group in an amount of 700 to 1700 mg per kg of a resin constituting the polyurethane resin, as a Si element amount contained in the silanol group. wherein the urethane resin comprised in the protective layer comprises a m-xylylene component; wherein the total proportion of the aromatic or aromatic-aliphatic diisocyanate in the polyisocyanate component of the urethane resin is from 60 to 100 mol%; wherein the oxazoline-group-containing resin in the resin composition for coating layer contains an oxazoline group amount of 5.1 to 9.0 mmol/g; and wherein the adhesion amount of the protective layer, the oxygen permeability and the oxazoline group amount are measured according to the methods in the description; with the proviso that the laminated film is not a laminate film comprising a coating layer, a metal oxide layer and a protective layer, with another intervening layer or without any intervening layer, laminated in this order on at least one surface of a polyester substrate film, wherein the coating layer comprises an oxazoline group-containing resin and a polyurethane resin, wherein the metal oxide layer comprises a composite oxide composed of silicon oxide and aluminum oxide, and wherein the protective layer comprises a polyurethane resin, the polyurethane resin contains a metaxylylene group in an amount of 20 to 33% by mass and a silanol group in an amount of 700 to 1700 mg per kg of a resin constituting the polyurethane resin, as a Si element amount contained in the silanol group.