PURPOSE: To enable a beginner and a skilled person to easily operate the device by displaying submenus hierarchically in order by an interaction means or setting data directly in an input field by a key input device.

CONSTITUTION: The main menu interaction means DM of the interaction means 6 displays a menu for the specification of operation objects and operation contents first. Then the submenu interaction means DS of the interaction means 6 displays a lower-order menu for operating one item in the main menu in hierarchically every time the item is specified on a screen indication device 3. When a field where data input by the key input device 2 is enabled is set for the items of the menus, the interaction means 6 enables the data input by the key input device 2. Consequently, the beginner can know the operating method for the operation items by opening lower-order menus in order and the skilled person can set data directly in the input field, so the operability is improved.