A color electrophotographic apparatus includes a photosensitive belt arranged obliquely, and a plurality of developing machines arranged on one side of the photosensitive belt in a stacked manner so as to be displaced from one another in a horizontal direction. The photosensitive belt is movable from below to above in a direction opposite to a direction of gravity when in a developing position. The developing machines include a non-magnetic, one component contact developing system having a developing roll for adhering toner on the photosensitive belt and a blade disposed below the developing roll for controlling an amount of toner adhering to the developing roll.