To obtain a tool for winding a core for performing miniaturization, saving space, and reducing the number of components and reducing the cost.

The tool 10 for winding a core is used to wind a conductive wire 40 around a T-shaped section 21. The tool 10 for winding a core has a core insertion hole 11a for detachably supporting the T-shaped section 21; and a plurality of terminal insertion holes 11b for detachably supporting a terminal pin, to which the end of the conductive wire 40 provided around the core insertion hole 11a is connected.