A rear end portion of a leading TAC film and a front end portion of a following TAC film are connected using a double-sided adhesive tape and a single-sided adhesive tape. A laser welding device emits a welding laser beam along a welding line onto the films. Owing to the welding laser beam, the leading and following TAC films are welded along the welding line. The laser welding device emits a cutout laser beam along a cutout line onto the films. Owing to the cutout laser beam, a part of the leading and following TAC films surrounded by the cutout line is cut out. The cut out part has the single-sided adhesive tape attached. Since the tape cannot be recycled, the cut out part is absorbed by an absorbing device and disposed.