PURPOSE: To prevent tubular band from abnormally elongating at transfer and make the smooth and sure transferring of tubular band possible by a method wherein cuts are made from the positions, each of which is somewhat inward from a side edge to central side, along a sealing line near both widthwise ends of tire synthetic resin tubular band.

CONSTITUTION: At the position near a sealing line (a) on the upstream side to transferring direction, cuts (b) and (b), each of which is inclined so as to position the nearer to central side to get the closer to the sealing line (a) side, are made from the positions, each of which is somewhat unward from time side edge of tubular band A to its central side, along the sealing line near both widthwise ends of the tubular band A with a trimming device 8. Next, an upside tongue piece 3a is produced with an upside sheet cutting device 9. Then, snap fasteners 4a are fitted up on a doubled portion consisting of the tucked-in upside tongue piece 3a and upside sheet 1a with an upside snap fastener fitting device 12. After that, an underside tongue piece 3b is produced with a cutting device 14. In succession, after the tip part of the underside tongue piece 3b is turned up, snap fasteners 4b, each of which fits to the snap fastener 4a, are fitted up on a doubled portion consisting of the turned-up tip part and the underside tongue piece 3b with an upside snap fastener fitting device 15.