Abstract: In a transfer system, a storage data and a specific equipment data indicating a specific equipment are generated. When a transfer command indicates the specific equipment as one of a previous location and a subsequent location, a priority level of the transfer command is increased. A transfer command having a highest priority level is selected. When an available carrier that is not assigned with a transfer command is not accessible within a previous area in which the previous location of the transfer command selected belongs to, when the priority level of the transfer command selected has been increased, and when an alternative carrier that is assigned with the transfer command and is transferring without carrying the cassette is accessible within the previous area, the transfer command selected is assigned to the alternative carrier.