Fiber bundle supply stop apparatus for spinning machine

In a fiber bundle supply stop apparatus for a ring spinning machine (11), a plurality of yarn break detectors (13) detects whether or not a yarn on a corresponding spindle (12) is broken, a position detector (15, 16, 24, 25) detects a position of a worker (W) or a machine providing yarn piecing service, and a controller (17, 21) controls fiber bundle supply stop devices (14) to estimate a time required for the worker (W) or the machine to arrive at a position of the spindle (12A, 12B) having a yarn break based on the detected position of the worker (W) or the machine, to continue supply of the fiber bundle to the spindle (12A, 12B) having the yarn break when the estimated required time is a predetermined value or smaller, and to stop supply of the fiber bundle when the estimated required time is greater than the predetermined value.