PURPOSE: To obtain appropriate image quality even in the case of forming an image on recording paper having different quality by preparing plural kinds of control information for forming the appropriate image for every different quality of an output medium, selecting the control information corresponding to the quality of the output medium set by a setting means from the outside and using it for forming the image.

CONSTITUTION: A copying machine is provided with two paper cassettes 10 and 11, and two kinds of copying paper can be used at the same time in this machine. The paper cassettes 10 and 11 are provided with paper kind information setting parts 1 and 2, respectively, and the paper kind information on the copying paper contained in the cassettes 10 and is set from the outside. When the paper cassettes 10 and 11 are set in a copying machine main body 12, the paper kind information is transmitted to a CPU 3 through an input interface 4. The CPU 3 controls a driving system 6, a developing part '7, a transfer part 8, and a fixing part 9 through an output interface 5 so that the optimum copying processing is performed to the copying paper based on the paper kind information. The various kinds of control information are stored in a nonvolatile memory.