Glass roll production method

A production method for a glass roll, in which a functional film is formed with a thermal film-forming device on a first glass film fed-out from an unwinding device to form a second glass film and the second glass film is wound by a winding device, the production method comprising:

• a start preparation step of feeding-out a first lead film coupled to a starting end portion of the first glass film from the unwinding device and allowing the winding device to wind the first lead film after passing of the first lead film through the thermal film-forming device;
• and
• a film-forming step of forming a functional film on the first glass film with the thermal film-forming device after the passing of the first lead film through the thermal film-forming device,
• wherein the start preparation step comprises a temperature increasing step of causing the thermal film-forming device to be increased in temperature to a film-forming temperature, and
• wherein, before the thermal film-forming device is increased in temperature to the film-forming temperature, the first glass film reaches the thermal film-forming device.