An image forming apparatus is provided. A development cartridge having a first memory storing therein cartridge information is detachably mountable to the image forming apparatus. The image forming apparatus includes: an apparatus casing and an exposure unit having plural light emitting portions. The exposure unit is supported by the apparatus casing so that the light emitting portions face a photosensitive member rotatably supported by the apparatus casing. The image forming apparatus further includes a reader unit disposed on the exposure unit and configured to read the cartridge information from the first memory when the development cartridge is mounted to the image forming apparatus.