To provide a data transferring device capable of smoothly transferring a large amount of data beyond an inter-controller transfer memory area with a relatively small capacity between the controllers by using the inter-controller transfer memory area.

This data transferring device is provided with a transfer area for transmission constituted of a data part for writing data to be transferred by one time transfer processing to a transfer destination device from among data to be transferred, which are written in an actual data storage part and a header part for writing the header information and a transfer area for confirmation for receiving the status information of the transferred data from the transfer destination controller, and for writing the data in the header part for the transfer destination controller. The data to be transferred the next are selected from the actual data storage part by referring to the transfer status information written in the header part of the transfer area for confirmation, and written in the data part of the transfer area for transmission, and the header information including the data transfer request is written in the header part of the transfer area for transmission.