A stitch monitor is a function of an embroidery machine that automatically tracks the status of both the upper and lower threads during operation. If a thread breaks or runs out from the bobbin, a special sensor immediately detects the problem and stops the machine's operation. This prevents embroidery without thread, which would lead to an incomplete or damaged pattern. After correction, for example, after threading a new thread, it is possible to continue embroidering precisely from the point of interruption.