A grounding member (20) is formed with a receiving hole (23), and a ground terminal fitting (10) is formed with a cantilevered lock (13) including a step (13B). The lock (13) is locked to the receiving hole (23) with the step (13B) contact with a stopper (24) of the receiving hole (23). In tightening a first bolt (51) at a first mounting hole (151) and a first female screw hole (51), a rotational force in a direction to bring the step (13B) into contact with the stopper (24) is applied to a terminal main body (11). Butting portions (14) protrude from side edges (13D) of the lock (13) and prevent following rotation of the terminal main body (11) by contacting receiving surfaces (25) when the first bolt (51) is tightened.