A bridge apparatus is disclosed, the bridge apparatus being connected between a first network and a second network and achieving a communication between equipment connected to the first network and equipment connected to the second network. This apparatus accepts communication from the equipment over the first network to equipment disconnected from the second network, and then, preserves contents of the communication even in the case where the equipment over the second network has been disconnected from the second network for reasons such as electric power cut. In the case where the disconnected equipment has been connected to the second network again, this apparatus transmits the accepted contents of the communication to the reconnected equipment.