To cope with the change and improvement of a system with good flexibility by informing a mobile robot of a carry-out request or a carry-in request to which information required for carrying out and in is attached, when a carry-out request or a carry-in request from the respective processes of manufacturing line are sent.

First, when a carry-out or carry-in request is generated in a storage 16, a contract agent 18 transmits an identification code of a transported, and an unloaded robot or a robot loaded with the transported article of all mobile robots 11-13, returns a reply to the effect that it can meet the carry-out or carry-in request to the contract agent 18. That is, there is provided the contract agent 18 having a function of informing all of mobile robots 11-13 of the effect that the request is given when a carry-in or carry-out request is given from an arbitrary storage 16, and a function of giving an instruction of performing the carry-in and carry-out operation to a mobile robot which returns the effect that it can cope with the information, so that it is possible to flexibly cope with an increase or decrease in the number of the mobile robots.