In an exposure device, a light source device having multiple light emitting devices arranged in one-dimensional or two-dimensional directions projects light against an image bearing member. A light source holding member holds the light source device in place. An optical device condenses the light projected from the light source device onto the image bearing member. An optical device holding member holds the optical device to maintain a predetermined gap between the optical device and the light source device on the light source holding member. A positioning member supports the light source holding member above the image bearing member to maintain a predetermined gap between the image bearing member and the light source device on the light source holding member. When seen from a light emitting point of the light source device, a position at which the positioning member supports the light source holding member is opposite the image bearing member.