PURPOSE: To prevent generation of fluffs by directly driving a balloon breaker with its own motor and controlling the rotational speed to a level meeting the reeling speed of weft, thereby minimizing the friction between weft and balloon breaker.

CONSTITUTION: A weft reeled from a stationary drum-type end-measuring and storage apparatus is passed through a tapered cylindrical balloon breaker 26 and guided to a main nozzle for weft-insertion. In the above process, the balloon breaker 26 is rotated with its own variable-speed motor 28 at a rotational speed directed by a speed-directing part 37. The rotational speed is calculated in the speed directing part 37 by calculating a coefficient from the weft-insertion period from the start timing of weft-insertion to the arrival timing of the weft and calculating the speed from the coefficient, a preset winding number of a reel necessary for one-pitch of weft-insertion and the rotational speed of the loom. The relative difference of the reeling speed of weft and the inner circumferential speed of the balloon breaker 26 can be eliminated by driving the balloon breaker 26 at the above designated speed.