The present invention makes it possible to provide a film exhibiting an excellent
oxygen-
gas barrier properties and an excellent
moisture proofness, the film containing at least a multivalent
metal salt of a polycarboxylate-based
polymer (A), the film having the density which is not lower than 1.80 g / cm3; the surface ratio α [the peak surface S1 (3700 to 2500 cm−1) / the peak surface S2 (1800 to 1500 cm−1)] of an
infrared absorption spectrum which is not larger than 2.5; and the peak ratio β [the peak A1 (1560 cm−1) / the peak A2 (1700 cm−1)] of the
infrared absorption spectrum which is not smaller than 1.2, by means of applying a solution containing the polycarboxylate-based
polymer (A) and the multivalent
metal compound (B) to a substrate, thus obtaining a dried film, and thereafter treating the dried film with heat under predetermined conditions. Accordingly, the present invention makes it possible to provide packaging materials and packaging containers for not only foods which are required not to contact an
oxygen gas, but also foods, beverages, chemicals, pharmaceuticals, and precision
metal parts such as electronic parts, as well as members of
electronic equipment, all of which are required to be protected from
moisture.