PURPOSE: To provide a data transfer device which transfers a data block consisting of data elements in various lengths at high speed between devices different in an 'Endian' system.

CONSTITUTION: The data stansfer device is provided with an input circuit 11 receiving the data block of data structure including the data elements different in length from a transfer source, data structure conversion parts 12-14 assembling data received in the input circuit into the data elements and structure- converting them into the 'Endian' system of the transfer source, an output circuit 15 giving the data elements which the data structure conversion parts structure-convert to the transfer source, a data structure holding circuit 16 holding the data structure of the transferred data block, 'Endran' holding circuits 17 and 18 holding the 'Endian' of the transfer source and the 'Endian' of a transfer destination and a control circuit 10 controlling the data structure conversion parts.