PURPOSE: To surely detect separated pick finding at ending two separated yarn by means of a doubler, by providing a plurality of reflection type sensors in the vicinity of the doubling point of yarn, in a detecting device detecting separated pick finding of yarn.

CONSTITUTION: When yarn breakage is generated during winding by a doubler and the yarn YA is sucked and caught with a suction mouth from the package 11 on a traverse motion drum 9, the yarn YA becomes separated pick finding yarn YA1, YA2, and they are respectively guided to the respective ending parts 14, 14 of an ending device. A detecting device 20 for separated pick finding is provided on a yarn guide 17 as a doubling point in such device. The detecting device 20 is constituted by arranging reflection type sensors 21a-21c which are composed of light emitting diodes 22a-22c and phototransistors 23a-23c, and mutually different in light emitting frequency. Light emitting signals are input to BPF so as to pass the band of the light emitting frequency, and the output are compared with reference voltage by means of a comparator so as to detect existence of yarn.