An image forming apparatus includes a detachably replaceable image forming unit for forming an image on a medium, the image forming unit including a component for forming the image on the medium and a first storage section for storing life information, use amount information, and use purpose information of the component; a read-write section for reading and writing information in the first storage section; a life management section for managing life of the image forming unit; and a second storage section for storing the life information and the use amount information read from the first storage section by the read-write section; the life management section rewriting the life information stored in the first storage section by the first storage section in accordance with the use purpose information stored in the first storage section and the use amount information stored in the second storage section.