PURPOSE: To surely prevent image jitter by preventing a developing means from moving in the case of exposure as to a color image forming device and a color image forming method.

CONSTITUTION: Cams 23, 24, 25 and 26 and springs 33, 34, 35 and 36 are provided, which allow developing devices 13, 14, 15 and 16 to approach a photosensitive body 12 in order to make a gap roller abut on the photosensitive body 12 before the developing actions of the developing devices 13, 14, 15 and 16 and separate the developing devices 13, 14, 15 and 16 from the photosensitive body 12 by a specified distance after finishing the developing actions of the developing devices 13, 14, 15 and 16. The length of an image non-formed area along the rotating direction on the peripheral surface of the photosensitive body 12 is made longer than the length on the peripheral surface of the photosensitive body from the specified exposing position to the developing device 16 positioned on the downmost-stream side in the rotating direction of the photosensitive body.