A data transfer device (10) converts the data stream input to it by IEEE 1394 isochronous transmission from an image processing device (20) connected to it into data in a color signal mode adapted to PCI transfer by means of a converter circuit (219), while controlling an address of PCI bridge circuit (216B) as bus master, transmits the image data from the converter circuit (219) to a graphic memory (221) by DMA transmission by way of a PCI bus (215) and writes the data in the graphic memory (221) by means of a graphic control circuit (220). It then reads the image data from the graphic memory (221) by means of the graphic control circuit (220) and transfers the data to an electronic device (30).