The method of producing a film includes the steps of: casting a dope
prepared by dissolving a macromolecular material in a solvent on a
casting band; stripping the cast dope from the casting band to form a
film; subjecting the stripped film to tentering to stretch or regulate
the same in its width direction; and subjecting the tentered film to roll
drying to dry the film while conveying the same in such a manner that it
engages with a plurality of rolls, the method being characterized in that
the solvent content in the film at the beginning of roll drying after
tentering is kept within the range of 3 to 8% by weight, the surface
temperature of the film during the roll drying is kept within the range
of the film's Tg (glass transition temperature) -15.degree. C. to the Tg,
and the rate of the film expansion in the film conveying direction is
kept within the range of -2% to 3%. Thus, the method enables both
wrinkles and cast non-uniformity occurring on the film surface to be
improved utilizing the tentering and roll drying steps of the
conventional solvent casting method without any modifications, while
avoiding the decrease in productivity.