PURPOSE: To conduct movements smoothly when a carrying truck is received into a transfer device and when the carrying truck is released from the transfer device by providing a guide cam device which turns the transfer device around a shaft center in the moving direction of the carrying truck.

CONSTITUTION: A transfer device 32 reaches a recovery portion 31 by self- propulsion. On this occasion, when the transfer device 32 is located on the terminal end side of a supply conveyer 23, the roller 64 of a support body 53 fits into the lower level guide groove 62 of a guide cam device 33, and so as to receive a carrying truck 8 easily, the support body 53 turns around the shaft center of a rotary shaft 52 and inclines in such a way that the tip side of the carrying direction of the carrying truck 8 falls downward. When the roller 64 comes to a center level guide groove 61, the support body 53 becomes horizontally poised. When the roller 64 comes to an upper level guide groove 63, it turns around the shaft center of the rotary shaft 52 and inclines so as to make an easy release, in such a way that the side to the recovery portion 31 of the carrying truck 8 falls downward, and the carrying truck 8 is released to the recovery portion 31 and propels itself under its own weight.