There is provided a data transfer method in an IEEE1394 system including a band request node and a transfer band management node. The method includes generating, at the band request node, a transfer request that can detect a data amount of transfer data and transmitting the transfer request from the band request node to the transfer band management node, determining, by the transfer band management node, whether a transfer band requested by the transfer request is ensured or not, notifying, from the transfer band management node, the band request node of the determination result, and transferring data from the band request node according to the determination result.