The present invention relates to a plastic film for medical containers having an oxygen absorbing function including at least 4 layers (4) and formed by a co-extrusion method, and an infusion bag formed thereof, in which the 4 layers include: a first layer (1) constituted by a polyamide obtained by a ring-opening polymerization of a lactam 11 or more carbon atoms or by polycondensing of an ω-amino acid having 11 or more carbon atoms, or a polyamide obtained by copolycondensing a dicarboxylic acid having 10 or more carbon atoms and a diamine having 6 or more carbon atoms; a second layer (2) of a mixed composition that is adjacent to the first layer and contains an ethylene vinyl alcohol copolymer of an α-olefin and a monomer of an unsaturated carboxylic acid or an anhydride of an unsaturated dicarboxylic acid as the major component, and a transition metal salt and a polyene-based polymer having an unsaturated double bond as accessory components; a third layer (3) that is adjacent to the second layer and contains a copolymer of an α-olefin and an anhydride monomer of an unsaturated carboxylic acid or an unsaturated dicarboxylic acid as the major component; and a sealing layer containing a polyethylene as the major component.