To provide a yarn sag removing device in a textile machine capable of forming a package having the consistent quality by realizing the consistent rotational resistance of a tightening roller of a threading member.

The yarn sag removing device 12 comprises a yarn-tightening roller 21 which is rotated while a spinning yarn 10 is wound around an outer circumferential surface and stored thereon, and a threading member 22 which is mounted on the yarn-tightening roller 21 in a concentric and relatively rotatable manner thereto. A columnar part 35 to match its axis with the axis of rotation is provided on a flyer shaft 33 of the threading member 22, a permanent magnet 36 is provided on an outer circumferential surface of the columnar part 35, and a hysteresis material 37 is provided in a facing manner in the radial direction. A cylindrical adjustment bolt 32 with the hysteresis material 37 installed thereon is screwed to a nut member 31 fixed to the yarn-tightening roller 21 side, and the facing area of the permanent magnet 36 and the hysteresis material 37 can be changed by rotating the adjustment bolt.