PURPOSE: To provide an inferior weft yarn treatment method in a weaving machine, when succeeding weft yarn does not reach a inferior weft yarn collecting unit, supplying another succeeding weft yarn from a weft yarn length measuring and holding unit and making the inferior weft yarn collecting unit repeat the collecting action of the inferior yarn, capable of reducing a number of stoppage of the weaving machine for a good production efficiency.

CONSTITUTION: In a method of treatment of inferior weft yarn, generating commands to stop a weaving machine and reaction of a cutter based on a signal of occurring of mistake in weft insertion from a weft yarn filler, as well as making generation of an air flow for preventing the weft insertion from an inferior weft yarn blow nozzle, leading succeeding weft yarn capable of being supplied from a weft yarn length measuring and holding unit to a guide of an inferior weft yarn collecting unit to detect a presence or absence of the succeeding weft yarn with a succeeding weft detecting means, if succeeding weft yarn is not detected, the succeeding weft yarn is further sent from the weft yarn length measuring and holding unit and is treated repeatedly.