<p>An image reader (100) has a removal memory device (2) in which authentication information for authenticating a user is stored. An image reader body (1) has authentication means that authenticates the user by comparing authentication information (8) stored in the removal memory device (2) with authentication information (9) pre-registered in the image reader (100). Only when authenticated by the authentication means, the user reads a document (3) using the image reader (100) and adds digital signature and approval information to image the data (15) that is read.</p>
