To provide a production method of an optical film, by which fluctuations in film thickness within an optical functional layer can be suppressed even when the optical functional layer is made thin in a nanometer order.

The production method aims to produce an optical film having at least one layer of an optical functional layer with a film thickness of 1 to 1000 nm formed on a substrate. The method includes: a step (1) of preparing a coating liquid containing a polymer; and a step (2) of applying the coating liquid on a substrate at a predetermined temperature and a predetermined speed to form a coating film. A glass rod having an outer diameter of 6 mm is vertically dipped into the coating liquid to 3 cm depth and vertically pulled upward at the above predetermined temperature and the predetermined speed to measure a stringing length of the drawn liquid from the coating liquid when the drawn liquid breaks. In five times of measuring the stringing length, an average stringing length is 5 cm or less.