drying zone 12 the solvents remaining in the filmy object such as the dichloromethane broken out of triacetyl cellulose by the swelling action is evaporated consequently in the production line 1 the evaporation of the solvent in the filmy object is promoted and the remaining amount of dichloromethane in the filmy object having passed the delivery zone 12 can be reduced to be 0 1 wt or less and simultaneously the total residual amount of the solvent is also reduced to be 0 5 wt or less in the downstream section 12 b of the late stage drying zone 12 the filmy object is cooled down to room temperature and the filmy object tac film takes the form of the finished tac film product the filmy object tac film discharged from the late stage drying zone 12 is wound by the winding device 500 the tac film thus produced is subsequently delivered to the subsequent processes unshown in the figure and is commercialized as the optical functional films such as protective film for polarizing plate and anti glare film additionally polarizing plate is formed by attaching the protective film for polarizing plate onto both sides of a polarization element made of polyvinyl alcohol etc and a part of a liquid crystal display is made by using the polarizing plate now with reference to fig2 description will be made below on the production line wherein cellulose film is produced by flow casting of the polymer solution onto.