An operation device comprising: a touch panel that displays a predetermined screen, and, when a key representing a predetermined name has been pressed on the screen, receives an input of a setting condition regarding the key; storage portion that stores as a table a name of a function corresponding to a key displayed on the screen and an alternative name in association with each other, the alternative name being different from the name and representing a function substantially equivalent to the function of the name; display reception portion that, if an alternative name exists for a name in the table, displays, near a key of the name for which the alternative name exists, the alternative name corresponding to the name; determination portion that, when the display reception portion has displayed the alternative name, determines whether or not a degree of similarity between the displayed alternative name and the name corresponding to the alternative name is high; and stopping portion that, if the determination portion determines that the degree of similarity between the alternative name and the name is high, stops the display of the alternative name after satisfaction of a predetermined stopping condition, wherein if an alternative name exists for a name in the table, the display reception portion displays, near a key of the name for which the alternative name exists, an alternative name key so that the alternative name key can be pressed, and when the alternative name key has been pressed, the display reception portion displays the alternative name near the key near which the alternative name key has been displayed, the predetermined stopping condition is that the number of times an alternative name key of a key of a name that matches some of characters of the alternative name has been pressed has reached a predetermined number of times, or that a predetermined period has elapsed since the alternative name key has been pressed for the first time, and even if the predetermined stopping condition is satisfied, if the determination portion determines that the degree of similarity between the displayed alternative name and the name corresponding to the alternative name is low, the display reception portion constantly displays the alternative name. a touch panel that displays a predetermined screen, and, when a key representing a predetermined name has been pressed on the screen, receives an input of a setting condition regarding the key; storage portion that stores as a table a name of a function corresponding to a key displayed on the screen and an alternative name in association with each other, the alternative name being different from the name and representing a function substantially equivalent to the function of the name; display reception portion that, if an alternative name exists for a name in the table, displays, near a key of the name for which the alternative name exists, the alternative name corresponding to the name; determination portion that, when the display reception portion has displayed the alternative name, determines whether or not a degree of similarity between the displayed alternative name and the name corresponding to the alternative name is high; and stopping portion that, if the determination portion determines that the degree of similarity between the alternative name and the name is high, stops the display of the alternative name after satisfaction of a predetermined stopping condition, wherein if an alternative name exists for a name in the table, the display reception portion displays, near a key of the name for which the alternative name exists, an alternative name key so that the alternative name key can be pressed, and when the alternative name key has been pressed, the display reception portion displays the alternative name near the key near which the alternative name key has been displayed, the predetermined stopping condition is that the number of times an alternative name key of a key of a name that matches some of characters of the alternative name has been pressed has reached a predetermined number of times, or that a predetermined period has elapsed since the alternative name key has been pressed for the first time, and even if the predetermined stopping condition is satisfied, if the determination portion determines that the degree of similarity between the displayed alternative name and the name corresponding to the alternative name is low, the display reception portion constantly displays the alternative name.