A network configuration control method and a configuration control unit enable configuration reservations of a network. Simultaneous reservation of opening and closing of a network section is performed if the same network section is not in operation at the time of opening and if there is no previous reservation for the same network section between time of the opening and time of the closing. Further, simultaneous reservation of closing and opening of the network section is performed if the same network section is in operation at the time of the closing and if there is no previous reservation of the same network section between time of the closing and time of the opening. Furthermore, when a network reservation is to be cancelled, a cancellation is performed if there is no reservation of the same network section after reservation time of the reservation to cancel, or if, in the case that there is a previous reservation of the same network section after reservation time of the reservation to cancel, the previous reservation may be cancelled.