To implement a thin wire inserting device into a ferrule capable of passing a plurality of thin wires through a ferrule having a fine center hole, if the thin wire is passed through the ferrule, in the case where the ferrule mounted to an end of an optical fiber is processed when the optical fiber used as a communication wire passage is connected to another device.

A ferrule fixing means 7 positions and fixes the ferrule 5 in order to pass the thin wire 3 through the ferrule 5. The thin wire 3 is fixed to a thin wire guide means 8 at a straight. In such state, the ferrule fixing means 7 and the thin wire guide means 8 approach by a thin wire feed means 10. Subsequently, the thin wire feed means 10 leaves the ferrule fixing means 7 and the thin wire guide means and when it leaves them, the thin wire guide means 8 releases the thin wire 3. When this action is repeated, the thin wire 3 advances in the center hole 6 of the ferrule 5. When the thin wire 3 passes through the ferrule 5, a leading edge of the thin wire 3 is fixed by a thin wire fixing means 9 and the ferrule 5 is moved toward a spool 4. Thereafter, the ferrule 5 and the thin wire 3 are positioned again and this action is repeated.