To carry works by one kind of truck without reloading in a paint line where the carrying height of a work carried on the truck from a conveyor rail is changed at a specified position.

A truck 2 is provided with a vertically movable attachment 2A attached to a base 2B traveling on a conveyor rail 3 for supporting a work W via an elongated/contracted support 2P. By using this truck, to change the carrying height of the work W during carrying, for example to carry the work in a lower position like a paint booth 4, the attachment 2A is positioned low. To carry the work in a high position like a drying furnace 5 for performing out-of-furnace carrying, the attachment 2A is guided to a specified height by an auxiliary rail 6 laid along the conveyor rail 3, and the support 2P is elongated/contracted. Thus, even in a paint line where a carrying height from the conveyor rail 3 is changed in a specified position, the work W is carried by one kind of truck 2, and reloading is unnecessary.