In a data transfer device that communicates with a communication device via a network, the storage controller controls reading data from and writing data to a plurality of storages. The correspondence information manager manages correspondence information manager to manage correspondence information between data written by the storage controller and a storage to which the data is written. The storage manager manages an invalid storage being a storage that the storage controller failed to read or write data. The communicator receives an acquisition request message for data from the communication device. The specifier specifies a storage storing the data requested, according to the correspondence information. The reader requests the storage controller to read the data from the storage specified by the specifier when the storage does is not the invalid storage, and not to request the storage controller to read the data when the storage is the invalid storage.