PURPOSE: To provide control of copying for non-impact printing that prohibits the output of the output letter data pattern when blanking instruction that is applied to a specified field of a specified form is read in the form overlay information and conducts printing output of copying slip type.

CONSTITUTION: A reading means 7 for blanking instruciton information and a gate 8 that prohibits the read-out output of a buffer 4 are installed and blanking instruction information is beforehand added to the form overlay information of the memory 1. When such a form overlay information is read out, it is detected by the deciphering means 7. The gate 8 is closed while in field, and the letter data can be deleted from the output bill by suppressing the letter data pattern from the buffer 4.