An operating method of a display device is provided. The method includes: recognizing, by the display device, a user's function control voice for controlling a function of a peripheral device; controlling, by the display device, the peripheral device to perform a function corresponding to the recognized function control voice in the peripheral device through a remote control device; and providing, by the display device, a control state of the peripheral device representing that the function corresponding to the recognized function control voice is performed in the peripheral device.