To provide a method for manufacturing a cellulose acylate film having excellent strippability of a dope film, free of film breakage in web handling and free of leaching of an additive and to provide a cellulose acylate film and a polarizing plate having excellent optical properties such as planeness and transparency.

There is described a method for manufacturing a cellulose acylate film by casting a cellulose acylate dope solution containing an ethylenically unsaturated monomer and/or an ethylenically unsaturated monomer having a functional group and a photopolymerization initiator from a casting die on a casting support. When the dope solution on the casting support is irradiated with UV, the concentration of oxygen in an UV irradiation booth is regulated to ≤10%. A cellulose acylate film obtained by the method and a polarizing plate using the film are also provided.