A drawer unit moves in a moving direction between an internal position inside the main housing and an external position outside the main housing. The drawer unit includes a drawer frame, a first exposure head, and a second contact member. The first exposure head moves between a first adjacent position at which the first exposure head is adjacent to the first photosensitive drum and a first spaced position at which the first exposure head is farther spaced away from the first photosensitive drum than at the first adjacent position. The second contact member is a part of the drawer unit other than the first exposure head. The first exposure head moves from the first adjacent position to the first spaced position due to a contact between the first contact member and the second contact member when the drawer unit moves from the internal position to the external position.