PURPOSE: To ensure the insertion of a fiber bundle into a rotary pipe, by providing an outlet of a rotary pipe with an ejection nozzle to eject air in a specific direction and a pin for inhibiting the propagation of twist and protruded along the path of the fiber bundle.

CONSTITUTION: An air ejection nozzle 37 and a needle pin 38 protruding along a path 124 of fiber bundle are placed in a through-hole 36 connected to an outlet 119c of a rotary pipe 119. The air ejection nozzle 37 is directed in the tangential direction against the path 124 of the fiber bundle and is opened toward the direction separating from the rotary pipe 119. The twisting of the fiber bundle S in the rotary pipe 119 and the winding of the bundle S around the inlet part 119a can be prevented in the present apparatus.