A data transfer control device includes an ATA device-side I/F which transfers data between the data transfer control device and an ATA host through a bus ATABUS1, an ATA host-side I/F which transfers data between the data transfer control device and an ATA device through a bus ATABUS2, a first interface which transfers data through a first bus, and a transfer controller which controls data transfer among the device-side I/F, the host-side I/F, and the first interface.