Lower thread winding apparatus characterized by automatically threading a lower thread into the corner portion of a bobbin shell

Provided is a lower thread winding apparatus capable of automatically threading a lower thread into the corner portion of a bobbin shell. After the winding mechanism 101 causes the lower thread S to wind around the bobbin 30, the control portion 500 allows the hook rotating plate 120 of the engaging mechanism 102 to rotate for pulling the lower thread S out of the bobbin shell 10 to be engaged with the engaging groove portion 131, and the bobbin shell holding mechanism 200 causes the bobbin shell 10 to move, so as to allow the lower thread S to be threaded into an insertion path 22 of the corner portion 20 and inserted into the thread inserting hole 21.