A method of controlling information apparatus is provided. Illumination devices are displayed in room units. In response to a selection of a first illumination device in a first room unit, a first room corresponding to the first room unit is displayed with first brightness not lower than second brightness of a background image when the first illumination device is in an on-state. In response to a selection of the first illumination device, the first room is displayed with third brightness lower than the second brightness when the first illumination device is in an off-state. A first control command is output to network for turning off power of the first illumination device, when the first room with the first brightness is selected. A second control command is output to network for turning on power of the first illumination device, when the first room with the third brightness is selected.