A display device capable of being connected to at least one external device, the display device comprising: a memory for storing multiple power control codes for controlling power's on/off of the at least one external device therein; a tuner for receiving a broadcast signal; a display module; an external device interface to be wiredly or wirelessly connected to the at least one external device; a network interface for performing bidirectional communication with a server storing a control code set for controlling the at least one external device; a user input interface for performing bidirectional communication with a remote controller; and a controller for controlling the memory, the tuner, the display module, the external device interface, the network interface, and the user input interface, wherein the controller is configured to: transmit a power control code to the external device through the remote controller after the at least one external device is connected to the external device interface; receive the control code set including the power control code from the server through the network interface and transmit the control code set to the remote controller when the external device is turned off in response to the power control code; and transmit another power control code of the stored multiple power control codes to the external device through the remote controller when a signal is continuously received from the external device. a memory for storing multiple power control codes for controlling power's on/off of the at least one external device therein; a tuner for receiving a broadcast signal; a display module; an external device interface to be wiredly or wirelessly connected to the at least one external device; a network interface for performing bidirectional communication with a server storing a control code set for controlling the at least one external device; a user input interface for performing bidirectional communication with a remote controller; and a controller for controlling the memory, the tuner, the display module, the external device interface, the network interface, and the user input interface, wherein the controller is configured to: transmit a power control code to the external device through the remote controller after the at least one external device is connected to the external device interface; receive the control code set including the power control code from the server through the network interface and transmit the control code set to the remote controller when the external device is turned off in response to the power control code; and transmit another power control code of the stored multiple power control codes to the external device through the remote controller when a signal is continuously received from the external device. transmit a power control code to the external device through the remote controller after the at least one external device is connected to the external device interface; receive the control code set including the power control code from the server through the network interface and transmit the control code set to the remote controller when the external device is turned off in response to the power control code; and transmit another power control code of the stored multiple power control codes to the external device through the remote controller when a signal is continuously received from the external device.