PURPOSE: To keep the compatibility with an external device different in printing processing and to easily print data without requiring a troublesome work.

CONSTITUTION: A word processor 11 is provided with the printer mode for printing of print data generated by a personal computer 12; and when this printer mode is set, the print processing corresponding to the personal computer 12 is executed to print the printing data of the personal computer 12 by a printer 11a in the word processor 11. Thus, data is easily printed without requiring the troublesome work, for example, reading the print data, which is generated by the personal computer 12, through a storage medium like an FD neither using text conversion software.