Bases (10) for guiding a movable end (37) of a conductor path (30) have a cross section along a direction normal to a parallel direction to guide rails (12) that is constant over the entire length. Thus, the bases (10) can be obtained by cutting an elongated raw material to a specified length in conformity with a vehicle type, thereby enabling a cost reduction. Further, since the bases (10) are symmetrical with a moving path of the movable end (37) located therebetween, it is sufficient to prepare only one kind of elongated raw material. In this respect as well, costs can be reduced.