PURPOSE: To attain the transmission of data to a single circuit regardless of the telegram length by producing a telegram with use of the telegram length defined for each transfer partner.

CONSTITUTION: A control information retrieving device 2 retrieves a control information part of a storage 5 based on the transfer partner name received from an input identifying device and acquires the necessary telegram length to send it to a telegram producing device 3. The device 3 has an access to a data part of the storage 5 based on the file name received from the device 2 and compares the data part with the telegram length received from the device 2. If the record length is larger than the telegram length, the data are transferred to a circuit sending device 4 by an amount equal to the telegram length. If the record length is smaller than the telegram length, a single record is read out of the data part of the storage 5. Then the length equal to two records is compared with the telegram length. If the record length is smaller than the telegram length, another record is read and added to the original record. Then this record length is compared with the telegram length.