PURPOSE: To print immediately after printing data are completely transmitted by sending a printing instruction to a designated printer after a printer start instruction is supplied, and then transmitting the printing data.

CONSTITUTION: When any one of the printers 21, 22, 23 is used to print, a CPU 4 first detects whether a printer is designated. When it is detected that a printer is designated, e.g., the printer 21 is designated, a printer start instruction is sent to the printer 21. Then, it is detected whether or not a printing form, etc., is completely set. In order to set the printing form, etc., for example, an operator manually inputs the form, etc., through a keyboard based on a program preliminarily stored in a ROM 5. When it is detected that the printing form, etc., is finished to be set, a printing instruction is fed to the designated printer 21. After a response to the printing instruction that printing is possible is sent back from tone printer 21, printing data are started to be transmitted to the printer 21.