A multi-function peripheral as an image processing device according to the present invention is wirelessly connected with a mobile terminal having a display and is capable of accepting an operation by a user via the mobile terminal. For this, a terminal side setting screen for operating the multi-function peripheral is displayed on the display of the mobile terminal. The terminal side setting screen includes buttons for an operation requiring the user to be in the vicinity of the multi-function peripheral. These buttons are brought in a mode capable of accepting the operation, when an estimated distance between the multi-function peripheral and the mobile terminal is less than or equal to a threshold value, whereas are brought in a mode incapable of accepting the operation, when the estimated distance exceeds the threshold value.