To provide a manufacturing process of an optical film which has a wide film width with its casting width of 1,500 mm and is free from the problem of shading caused by the surface defects, when incorporated in display equipment and the optical film.

The manufacturing process of the optical film comprises extruding a molten cellulosic resin in a film form through the casting die of an extruder, cooling and winding the film obtained. The film has a casting width of 1,500 mm. The height and inclination of the ruggedness over the entire surface of the film except for the selvages as wide as 100 mm before stretched is 300 nm and 300 nm/mm respectively.