The present invention provides a support film for solution film forming, said support film combining polymer solution leakage properties during a solution film forming step, early separation resistance during a drying step and wetting step, and easy release properties when intentionally separating a polymer film. Provided is a support film for solution film forming, said support film being formed by introducing fluorine atoms to at least one surface of a base film that is formed from one or more types of polymers selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene napthalate, polyphenylene sulphide, polysulfones, polyether ketone, polyether ether ketone, polyimides, polyetherimide, polyamides, polyamide-imides, polybenzimidazoles, polycarbonates, polyarylates, and polyvinyl chloride. Therein, the ratio, measured by X-ray photoelectron spectroscopy, of the number of fluorine atoms/the number of carbon atoms in the surface to which the fluorine atoms are introduced, i.e. the modified surface, is 0.02-0.8, inclusive.