A display device that can be used with another display device, includes: a display unit; a command receiving unit which receives a control command or ID information from an external remote controller; and a command processing unit. The display unit displays the display device's own ID in response to reception of the control command by the command receiving unit. If the command receiving unit receives the ID information indicating the display device's own ID after the display unit starts displaying the display device's own ID, the command processing unit performs processing corresponding to the control command.