A display device capable of upgrading smart functions as broadly described herein may include a multi-functional display device capable of upgrading smart functions, including a broadcast receiver for receiving a broadcast signal, a demultiplexer for demultiplexing the received broadcast signal, a decoder for decoding the demultiplexed broadcast signal, a display for displaying the decoded broadcast signal, an external device interface configured to connect to a smart card for receiving upgrade data, a memory for storing the upgrade data and version information of the smart card, and a controller configured to process and display the received broadcast signal on the display, determine whether the smart card is connected to the display device, and communicate with the smart card to operate the multi-functional display device, wherein the smart card includes at least one smart function for execution on the multi-functional display device.