An overhead transport vehicle system includes an overhead transport vehicle to convey an object, and a teaching unit to teach transfer of the object by the overhead transport vehicle to a load port on which the object is to be placed. The teaching unit includes a body including a detector to be brought into contact with a positioning pin on the load port to detect a position of the positioning pin, and a flange movable up and down with respect to the body and to be held by a holder to be raised and lowered by an elevator of the overhead transport vehicle.