PURPOSE: To fix an end part of a fiber bundle by nipping at least one-end parts of many fibers in the radius direction so as to gather the fibers to form a prescribed shape, and pressing and fixing a thermoplastic resin plate having the heated and melted surface to the gathered end parts.

CONSTITUTION: At least one-end parts of many fibers accumulated in a bucket 4 are gathered in the radius direction by a gathering device 6. The surface of a thermoplastic resin plate is pressed and fixed to the end parts of the gathered many fibers while heating and melting the surface of the plate by a fixing device 89 to fix the end parts of the fiber bundle F. The formed fiber bundle is dropped from a taking-out position into a box b, and encased.