To provide a weft treating device provided with an blowing-up means for upwardly blowing wefts connecting to following mispicks to a suspend them via jetted air and capable of surely conducting an automatic removing treatment of the mispicks.

This weft treating device is formed by installing a blowing-up nozzle 17 just under a weft-inserting main nozzle 12 and oppositely mounting a suspending position control cylinder 18 right over the nozzle 12, by fixing a clamp 22, supporting the cylinder 18, via fastening of a screw 23 to a base frame 20 engaged with the upper frame 32 of deformed dents 13 and by fixing the cylinder 18 to the clamp 22 via fastening of the screw 23, wherein the upper opening of the cylinder 18 is provided with a metal net fixed thereon and covered by a metal net 24.