An image forming apparatus includes an image bearing member. First and second developing devices developing a latent image formed on the image bearing member. A rotary member holds the first and second developing device. First and second drive receiving parts are provided at first and second side plates at opposite end portions in a longitudinal direction of the rotary member. A rotary shaft includes first and second drive transmitting parts engaged with the first and second drive receiving parts. A driving source drives the rotary shaft, which is rotated by driving power is transmitted to the first and second drive receiving parts and the rotary member is rotated. The rotary member includes a connecting member which has a "" shaped section for connecting a center of the first side plate and a center of the second side plate.