thereafter the flow returns to step s 41 the process of the flow chart shown in fig1 is performed by the transmitting side replicater 12 for all container entries of the directory structure managed by the transmitting side server 11 next the process of step s 32 of the flow chart shown in fig1 will be described in detail with reference to a flow chart shown in fig1 all the process of the flow chart shown in fig1 is performed by the receiving side replicater 17 at step s 50 leaf update information msg x 1 that has been broadcast by the transmitting side replicater 12 through the broadcasting network 2 is received by the receiving side replicater 17 at step s 51 it is determined whether or not the leaf update information msg x 1 has been received at step s 50 first time when the determined result at step s 51 is yes namely the leaf update information msg x 1 has been received first time the flow advances to step s 53 at step s 53 the message id of the received leaf update information msg x 1 is stored as a copy 6 to the recording medium or the storing medium such as a memory or a hard disk of the receiving side replicater 17 thereafter the flow advances to step s 54 at step s 54 corresponding to the contents of the received leaf update information msg x 1 namely the difference update information contained in the leaf update information msg x 1 a relevant leaf entry of the directory information managed.