An image forming apparatus comprises: a rotary unit having a plurality of development devices provided around a rotary shaft, the development device including a constituent unit, wherein the plurality of the development devices move to a development position where the development devices sequentially oppose an image carrier by rotation of the rotary unit, and the development device in the development position develops an electrostatic latent image on the image carrier, a state detection unit that is disposed at a position above a circumference of the rotary unit, the position being different from the development position and that detects at least one of a state of the development devices and a state of the constituent unit of the development devices; and a rotation control unit that controls the rotary unit so as to perform rotation of the rotary unit for sequentially moving the development devices to the development position and rotation of the rotary unit for sequentially moving the development devices to a detection position during the same rotation.