PURPOSE: To easily and quickly produce a composite image with the memory capacity equivalent to one screen by writing an image which defines the position of a 2nd mark put on a 2nd original as a starting position at the start position of an image inserting area of an image memory by an amount equal to the size of the image inserting area.

CONSTITUTION: An image B of a 2nd original is read by an image reading means 4, and a position Pa of a 2nd mark is detected out of the image data by a mark detection means. Then an image write control means writes an image defining the position Pa on the original image B as a starting position by an amount equal to the size of an image inserting area of an image memory 2 at the starting position of the image inserting area that is calculated by a calculation means. Thus it is possible to easily and quickly produce an image composed from plural original images with the memory capacity equivalent to one screen.