1. A power saving method of a display apparatus, the power saving method comprising: receiving a broadcasting signal corresponding to a channel selection command by a tuner; outputting a video signal and an audio signal of the received broadcasting signal; acquiring an image by photographing surroundings of the display apparatus; detecting a human body region contained in the image by analyzing the acquired image; detecting a viewing state of the user by analyzing the human body region and determining if the human body region is detected in the image; entering a power saving mode when there is no user viewing the display apparatus by determining if the human body region is not detected in the image or when the user viewing the display apparatus is in a sleep state by determining if the eye region of the user is in a closed state, or if the motion of the human body region is not changed; initiating a storage of the broadcasting signal in a storage unit when the power saving mode is entered; and displaying a message to inform a user of the storage of the broadcasting signal in the storage unit when the power saving mode is canceled; wherein the detecting of the viewing state of the user includes: detecting a face region in the detected human body region; detecting an eye region in the face region; detecting an eye state of the user by analyzing the detected eye region; analyzing a motion pattern by analyzing a change in motion of human body regions detected in a plurality of images if the face region is not detected in the human body region; storing learning information to detect the human body region, the face region, and the eye region, to recognize an eye state, and to analyze the motion pattern; and analyzing the viewing state of the user based on the stored learning information; wherein the detecting of the face region depends upon results of the detecting of the human body region, wherein the detecting of the eye region depends upon results of the detecting of the face region, wherein the stored broadcasting signal comprises the video signal and the audio signal received from the selected channel, wherein a power is provided to the tuner for receiving the broadcasting signal in the power saving mode, and wherein the entering the power saving mode includes when it is determined that there is no user viewing the display apparatus for a predetermined time, only the output of the video signal is turned off while the output of the audio signal is maintained.