An image forming apparatus includes an exposure device as a light source, a developer container storing developer and attached to a main body of the image forming apparatus perpendicular to a lengthwise direction of the photoconductor, a developing unit and a photoconductor unit having a photoconductor for bearing a latent image thereon each detachably attached to the main body substantially in the same direction as the developer container. An exposure device displacing mechanism displaces the exposure device between a first position enabling the exposure device to function as the light source and a second position disabling the exposure device to function as the light source. The photoconductor unit is detached when the developer container is either displaced from an initially attached position or is removed from the main body and the exposure device displacing device has displaced the exposure device to the second position.