PURPOSE: To correctly control the feed length without loosening the seal material, by pulling the seal material against a tension of energizing spring while in brake motion of the reel shaft, and feeding the seal material from the reel in the method of return motion of the energizing spring following a release of the brake operation.

CONSTITUTION: When installed to a heat sealing machine, after a completion of heat sealing work, if released an electromagnetic brake 11, having applied a brake operation to a reel shaft of a reel 9, a seal material 14 is fed from the reel 9 by the return motion of a coil spring 13. A length of this fed seal material 14 comes to be the length of the seal material 14 pulled before by a seal material pulling roller device 5. To correctly regulate the rotation of a drive roller 22 of this seal material pulling roller device 5 can control a length of the seal material 14, fed from the reel 9, to the prescribed length.