PURPOSE: To write different data without contacting by temporarily storing write data from an external part into a first storage part and transferring stored data to a second storage part in accordance with the input of a transfer signal.

CONSTITUTION: A main memory 8 consists of a data rewrite area 8a where data can be rewritten, a read-only area 8b for data which is registered at the time of issuing a card and an identification code storage area 8c storing identification codes which are individually given to the respective cards. An identification code extraction part 4 extracts the identification codes from input data and transmits them to an identification code comparison part 9. When the extracted identification code and the code stored in the main memory 8 are compared and they coincide, a coincident signal is transmitted to a data processing control part 6. Furthermore, a buffer memory 5 sequentially transfers input data which is written to the data storage area 8c of the main memory 8 in accordance with a read control signal from a read/write control part 7.