There is provided a display device, which is capable of easily changing display information and of reducing power consumption. The control system of the display device is divided into a power supply control system, a main control system and a liquid crystal display panel driving system. When a main power switch 192 is turned on, only a sub-control circuit 170 as the power supply control system is supplied with power in a normal state. When an event relating to control of the display device 80 occurs, a power supply circuit 172 is set in an energized state to supply power to the main control system, setting the main control system in an active state. When the event relating to control of the display device 80 is accompanied by rewriting of display on a liquid crystal display panel, a liquid crystal power supply circuit 193 is set in an energized state to supply power to the liquid crystal display panel driving system.