An assembly/transport apparatus includes: a carrier on which a transport object is mounted; a transport track; a return track that overlies the transport track in a top/bottom direction; a first transfer device that transfers the carrier between the transport track and the return track; a second transfer device that transfers the carrier between the transport track and the return track; and a frame that supports the transport track, the return track, the first transfer device and the second transfer device. The transport track includes transport driving devices that cause the carrier to travel and stop. The return track includes return driving devices that cause the carrier to travel and stop. The first transfer device includes first transfer driving devices that cause the carrier to travel and stop. The second transfer device includes second transfer driving devices that cause the carrier to travel and stop.