To provide a data transfer technique in a file level capable of restraining performance degradation of request transfer processing.

An object ID includes sharing information indicating a sharing unit of a logical disclosure unit including one or more objects. Transfer determination information is prepared to express whether the transfer is finished or not for every sharing unit. An intermediate device holds the object ID in a transfer destination of the transferred file, and updates the transfer determination information to the information expressing that the sharing unit including the file is the transfer finished sharing unit. This intermediate device determines whether the sharing unit expressed by the sharing information in the object ID is the transfer finished sharing unit or not, by referring to the transfer determination information, when receiving a request data having the object ID, and transfers the request data having the transferred destination object ID corresponding to the file to a transfer destination device, when the file identified based on the object ID is the transferred file for the transfer finished sharing unit.