When a print switch is pressed, the color of the switch changes from green to orange. A wait indication prohibiting removal of an original placed on a platen glass is turned on. When reading of original images by an image reader is finished, the wait indication is turned off, permitting the removal of the original. Meanwhile, the color of the print switch is kept as it is until the end of image formation on a paper. The color of the print switch is turned into green when the image formation is finished, and the copying machine is returned to a stand-by state. Therefore, the next original can be set before the end of image formation, and the copying operation can be facilitated.