PURPOSE: To reduce a load of an operator, and improve operability by retaking an image automatically from the first sheet number to the prescribed addition sheet number when operation to cause a change in image information of a sample image is not carried out, and carrying out addition display.

CONSTITUTION: When an operator indicates image display in the addition sheet number of thirty two sheets, a host CPU10 informs a picture processor 7 of that effect. Next, when the operator indicates to move an image, the CPU10 informs a stage control circuit 9 of that indication, and at the same time, the CPU10 indicates the image display in the addition sheet number of one sheet to the picture processor 7. When the CPU10 detects a finish of stage moving operation by a response from the stage control circuit 9, the picture processor 7 displays automatically the image display in the former addition sheet number of thirty two sheets on a CRT12. When the operator indicates a change in image magnifying power, the CPU10 informs an electron optics system control circuit 8 of that indication, and the image magnifying power change is carried out instantly, and at the same time, indicated automatically retaking in the former addition sheet number of thirty two sheets to the picture processor 7.