PURPOSE: To provide a screwing device capable of connecting an electric wire to an electric element without miswiring.

CONSTITUTION: This device is provided with confirmation signal switches 3A and 3B provided on every screw threadedly engaged part of a member to be mounted, and giving offtake confirmation signals for electric wires corresponding to these screw threadedly engaged parts; fastening tools 1A and 1B outputting a described-value-reached signal when a fastening torque value reaches a prescribed value; and a fixing block 4 fixing a member to be mounted in a condition where the screw threadedly engaged parts are faced in a given direction. A fastening tool drive apparatus 9 is also provided which is to drive a fastening tool in order to screw a screw, for fixing the connection part of fusible links corresponding to given screw threadedly engaged parts and electric wire terminals to the member to be mounted, to the given screw threadedly engaged parts, making it a condition that the offtake confirmation signals for the electric wires corresponding to the given screw threadedly engaged parts are inputted at given order.