To restrain the fluctuation of the condition of a processing solution and to stabilize the quality of a print image by measuring the concentration of the principal component of a photographic processing solution in a preservation tank and appropriately correcting the quantity of the photographic processing solution discharged from the preservation tank in accordance with the measured result on the concentration of the principal component.

This automatic developing machine for photosensitive material having plural kinds of photographic processing solution preservation tanks is provided with a measuring means for measuring the concentration of the principal component of the photographic processing solution at least in one preservation tank, an arithmetic part arithmetically calculating the quantity of the photographic processing solution discharged from plural kinds of preservation tanks based on the measured result, and a control means for controlling the discharged quantity of the photographic processing solution based on the arithmetically calculated result.