To authorize any number of operators to output image data, while keeping secrecy of the image data stored in an apparatus.

An operator is selected from a displayed list of operators so as to be given an authorization of outputting a stored document, and a controlling means associates operator specifying information to specify the selected operator (a user code or the like) with a read image data, and stores the information in a HDD 71. When the operator selects the image he/she wants to output out of a displayed list of images and inputs his/her user code, the autorization means checks whether the selected image data is stored by associating with the user code, and printing is executed when the matching is confirmed.