To provide a constitution capable of improving the success ratio of capturing the yarn end in a pick finding device.

This yarn end treating device 11 includes a bobbin rotating mechanism 24, and a blowing nozzle 27. The bobbin rotating mechanism 24 rotates a yarn feeding bobbin 15. The blowing nozzle 27 jets air along a surface of the yarn feeding bobbin 15 toward an end part of the yarn feeding bobbin 15. The yarn end treating device 11 jets the air by the blowing nozzle 27 while rotating the yarn feeding bobbin 15 in the yarn winding direction. By this constitution, back wind yarn 22 is blown up by jetting air from the blowing nozzle 27, and is wound on an end part of a rotating bobbin tube 21. Thus, by winding yarn on the end part of the bobbin tube 21, the yarn of the yarn feeding bobbin 15 can be easily captured in a post-process.