An image forming apparatus includes a plurality of photosensitive drums and a plurality of developing rollers for developing latent images formed on the photosensitive drums, respectively. A switching unit switches positions of the plurality of developing rollers relative to the photosensitive drums, respectively, between developing positions for developing the latent images and spaced positions retracted from the developing positions. The developing rollers are capable of taking (i) a full spaced state in which all of the developing rollers are in the spaced positions, (ii) a partly developing state in which a portion of the developing rollers are in the developing positions, while the other is in the spaced position, and (iii) a full developing state in which all of the developing rollers are in the developing positions. The switching unit switches the positions of the developing rollers among the three states in a predetermined fixed order.