To obtain the subject film having low and stable retardation value in the thickness direction, and capable of providing a protective coat of a polarizing plate by using cellulose acetate having a specific value of a substitution degree at the specific position.

The subject film is obtained from an cellulose acetate having ≥2.67 total acetyl substitution degree at 2- and 3- and 6-position, ≤1.97 total acetyl substitution degree at 2- and 3- position. The cellulose acetate is swelled by an organic solvent (preferably containing ≥50 wt.% methyl acetate), cooling the swelled compound to (-100)-(-10)°C, thereafter heating the swelled compound to 0-200°C to provide an organic solvent solution of the cellulose acetate. This organic solvent solution is coated on a supporter to provide a cellulose acetate film. A polarizing plate protective coat of a liquid crystal display device having an excellent transparency and a low birefringence (a low retardation value) is obtained by using the film.