A manufacturing line for a semiconductor device according to the invention is a manufacturing line for manufacturing a semiconductor device by circulating a workpiece along a conveyance route on which a plurality of treatment devices are arranged. The conveyance route includes a first route on which the treatment devices with a large number of times of treatment are arranged, and a second route on which the treatment devices with a small number of times of treatment are arranged. Besides, the conveyance route makes a changeover between the conveyance of the workpiece that has moved along the first route to the first route in a continuous manner, and the conveyance of the workpiece that has moved along the first route to the second route.