Provided is an air permeation resistant film in which flexibility can be imparted to the film without remarkably increasing the proportion of a rubber constituting a dispersed phase. An air permeation resistant film comprising (A) a thermoplastic polyester elastomer which comprises a block copolymer containing a polyester as a hard segment and has a melting point of from 180 to 230° C., and (B) a rubber, in a mass ratio (A)/(B) of from 90/10 to 40/60, wherein the component (A) and the component (B) are melt-kneaded to perform dynamic crosslink, thereby forming a continuous phase composed of the component (A) and a dispersed phase composed of the component (B), and the film has an air permeation coefficient at 80° C. of 5×1013 fm2/Pa·s or less and Young's modulus of 120 MPa or less.