Memory interface means which can be easily removed by a user is included, use of a generally-available general-purpose memory is made possible and increase of the capacity of a memory which can be used by an image forming apparatus, image electronic data stored in a memory in the image forming apparatus, management information for managing the image electronic data, management information in the apparatus such as a telephone book used by facsimile means are can be bidirectionally copied or moved with the external memory in accordance with the user's operation or automatically.