Image forming apparatus configured so that an attachable and detachable storage medium is attachable thereto

An image forming apparatus to which an attachable and detachable storage medium is attachable, the image forming apparatus comprising:

• an operation unit configured to output an operation signal corresponding to an operation of a user;
• a document reading unit configured to read plural sheets of a document sequentially and generate image data of the document;
• and
• a control unit configured to control the document reading unit to start an operation for reading the document after having received an operation signal for reading the document from the operation unit, and to save identification information of the document and a destination to save image data of the document in the attachable and detachable storage medium, wherein after the identification information of the document and the destination to save image data of the document have been saved in the attachable and detachable storage medium, when reading of a preliminarily defined number of sheets in the document has been completed without the attachable and detachable storage medium being detached during the operation for reading the document, the control unit stops the operation for reading the document.