PURPOSE: To provide an electrophotographic copying machine preventing erroneous copying which occurs when a copying magnification is finely adjusted, on the electrophotographic copying machine whose automatic form selecting function is operated.

CONSTITUTION: The electrophotographic copying machine is provided with a mode specifying means specifying an automatic form selecting mode, a copying magnification setting means setting the copying magnification, a magnification finely adjusting means finely adjusting the set copying magnification in a prescribed unit, and the automatic form selecting means detecting the size of an original when the automatic form selecting mode is specified by the mode specifying means, selecting a proper copying paper size, from the detected original size and the present set copying magnification, and executing the copying on the relevant size copying paper. When the copying magnification is finely adjusted by the magnification finely adjusting means after the automatic form selecting mode is selected and the copying is executed in this mode, the copying paper size selected when the copying is executed is maintained.