PURPOSE: To facilitate write for a user and to simplify image data processing by erasing the data of a character frame by exclusively ORing slip layout and the image data of any arbitrary read slip.

CONSTITUTION: A data processing part 101a is provided with a function to exclusively OR the image data of the read slip and the layout data of the character frame of the slip registered on a slip layout registration part 112 and to output the data after the arithmetic as the image data of the slip. When the image data of the slip are read by a read part 104, the data are temporarily stored in an image memory 105. The data processing part 101a reads the slip layout data registered on the slip layout registration part 112 and the image data of the slip stored in the image memory 105. The data processing part 101a exclusively ORs the respective data so as to provide the slip image data from which character frame data are erased.