When a monochromatic copy mode is to be executed, a control section sets a read mode in a scanner section so as to enable the scanner section to read an image at high speed by means of only a line sensor K, sets in an image processing section an image process that can print monochromatic image information, which is sent from the scanner section, with a single black color in the printer section, and sets in the printer section a monochromatic print mode that can print a black image at high speed, thereby controlling a monochromatic copy operation.