An evaluation method and printer in which a maintenance man may easily identify a deteriorated component in addition to a component that is broken down or is remarkably hard to operate without the need for any additional complex detecting device. A printer has a control part which controls a mechanical part and judges quantitatively in which state among normal, deteriorated, and abnormal states each mechanical part component is located. This judgment will change in accordance with whether the printer is in a maintenance or a normal mode. Further, a deteriorated component can be determined by visually inspecting a copy after one or a combination of electric parameters have been set to printable upper and lower limits.