Patent ID: 8656737

Claim:
A glass film ribbon production method, comprising: forming a glass film ribbon while allowing a glass to descend; annealing, after the forming is executed, the glass film ribbon while allowing the glass film ribbon to descend in an annealer to remove an internal strain; cutting, after the annealing is executed, the glass film ribbon having a thickness of 300 μm or less at a center portion excluding both widthwise ends; and holding the descending glass film ribbon with cooling rollers located above and outside of the annealer, auxiliary tensile rollers located inside the annealer, and main tensile rollers located below and outside of the annealer, wherein the main tensile rollers, driven to rotate, hold the glass film ribbon after the annealing and before the cutting, a force by which the auxiliary tensile rollers hold the glass film ribbon is smaller than a force by which the main tensile rollers hold the glass film ribbon, and the glass film ribbon is provided with tension in a vertical direction between the main tensile rollers and the auxiliary tensile rollers.