A display operation device includes: a display-integrated operation panel; a first UI component display device displaying a read start key; a read activating device responsive to a user operation of the read start key, for starting a document reading process; a second UI component display device, responsive to activation of the document reading process, for displaying a read stop key in place of the read start key; and a reading process stopping device, responsive to a user operation of the read stop key, for stopping execution of the reading process. When reading ends, an additional read key is displayed in place of the read stop key. The background color of read stop key is selected to be much different from the background color of read start key, and the background color of additional read key is selected to be analogous to the background color of read start key.