It is an object of the present invention to provide a method for manufacturing a birefringent film that can reduce the amount of a remaining solvent in the birefringent film without degrading appearance uniformity or an alignment in its thickness direction. The method of the present invention for manufacturing an optical film includes the steps of: coating a base with a polymer solution obtained by dissolving a polyimide-containing polymer in a solvent so as to form a coating film; and drying the coating film so as to form a birefringent film, in which the drying step includes at least two stages of drying processes. The drying step preferably include two stages of the drying processes, and a temperature in the former stage of the drying process is preferably lower than a temperature in the latter stage of the drying process. If adding a step of providing the birefringent film with an anisotropy of a refractive index in an in-plane direction, a birefringent film with an optical biaxiality can be manufactured.