PURPOSE: To provide the method and device for detecting feeding stop of a lower thread capable of preventing the production of defective product by immediately stopping a driving motor when all the lower thread wound around the bobbin are fed out or the lower thread is not fed out due to the disconnection or the thread shortage.

CONSTITUTION: The sewing machine sewing the fabric detects the rotation of a bobbin 5 which rotates by the movement of the lower thread to be fed out coupled with the movement of the fabric at the time of sewing by a sensor 8, which is converted into an electric signal of the prescribed pattern and inputted into an arithmetic processor 9. When the rotation of the bobbin 5 stops, the driving machine motor in the sewing machine is designed to be stopped by a stop signal. The bobbin 5 is provided with a mark 5a for detecting the rotation winding the lower thread.