PURPOSE: To improve surface dimension stability in rough surface polyester film by limiting the peripheral speeds and the surface temperature of a plurality of rolls that come in contact with the film in polyester film shrinking processes.

CONSTITUTION: Two heating rolls are arranged in parallel with and adjacent to one non-heating roll and the interval in which a film does not touch the rolls does not exceed 5cm. When the inside or the outside of the film is brought into alternate contact with the surface of each roll, shrinkage of 2W10% is carried out in the running time of the film and the peripheral speeds of the rolls V1, V2...VN and the surface temperatures thereof T1, T2...TN satisfy formulas I W IVbetween the supply side of the film and the take-up side thereof.