A control method causing a computer of the information apparatus to: display a display screen on the display, the display screen representing a floor plan for one floor including at least two rooms; display device icons representing target devices on the display screen, the device icons including an illumination icon which represents illumination devices, the illumination icon being commonly used for the illumination devices installed in two or more rooms of the at least two rooms; and cause the floor plan represented by the display screen to function as an operation screen for controlling the illumination devices, and display a region of the floor plan with brightness less than specific brightness, when it is sensed that the illumination icon is selected, the region corresponding to a room in which an illumination device whose power is in an off state is installed.