To provide a color imaging apparatus, capable of realizing cost reduction and the improvement of reliability of the braking mechanism of a reliable rotary developing device at low cost.

This color imaging apparatus is equipped with a plurality of process cartridges obtained, by integrating a developing means and a developer storing container and attached to/detached from an imaging apparatus body, and also has the rotary developing device supporting a plurality of process cartridges and performing development, by successively rotating and moving the respective process cartridges at a position where an electrostatic latent image on an electrostatic latent image carrier is developed, in a state where it is opposed to the electrostatic latent image carrier. A braking unit (braking mechanism) B for braking a rotating body, supporting a plurality of process cartridges in attaching/detaching the process cartridges, is constituted of a gear 41a provided on the side plate 41 of the rotating body in order to make the rotating body rotate, a gear train for driving and rotating the gear 41a, and a gear for braking elastically pressed to one gear of the gear train, so that it can be separated from the brought into contact therewith.