To provide an apparatus and method for preparing a cellulose ester film having a thickness of less than 85 μm excellent in flatness and to provide a cellulose ester film for a liquid crystal image display device having a thickness of less than 85 μm excellent in flatness.

There is provided a method for preparing a cellulose ester film having a thickness of less than 85 μm by a solution-casting film-forming method, wherein cellulose ester dope is cast from a casting die 2 on a traveling support 3 for casting thereby to form a web 1, which is dried to form a film by exposure of the surface thereof to drying air 7 having an absolute value of a static pressure of 20-100 mmAq and a deviation of the static pressure between that in a width direction and that in a longer direction at an outlet of the drying air, of not more than ±20%.