Dope containing TAC and a solvent is prepared. The dope is cast so as to form three layers from a casting die. A casting film is formed on a cooling drum. The casting film is peeled as a wet film from a cooling drum by a peel roller. The wet film is transported by a pin tenter and a clip tenter. A tenter draw ratio, which is a ratio between feeding speeds of the pin tenter and the clip tenter and a rotating speed of the cooling drum, is set to not less than 110% and not more than 150%. The wet film is dried in the pin tenter and the clip tenter to obtain a film.