Provided is a device for manufacturing an optical film having satisfactorily reduced thickness unevenness, by using a melt-casting film forming method, which device includes a casting die for discharging a molten film-forming material including a thermoplastic resin into a film-like shape; a pair of a first rotation roll and a second rotation roll between which the discharged film-shaped molten article is pinched to be cooled and solidified to make the film-shaped molten article; and two pairs of wind shield plates each of which pairs are arranged between the shaft-direction ends of the first and second rotation rolls and an end part in the width-direction of the film-shaped molten article, wherein the wind shield plates are placed approximately perpendicular to the surface of the film-shaped molten article, and wherein each pair of the wind shield plates are placed approximately in parallel.