To obtain a power-saving control system for display device which can reduce the influence of a decrease in the visibility of screen display information without the need to change settings of the display device by a user every time the power-saving level to the display device varies.

This is a power-saving control system for display device 101 which performs power-saving control over display device 101 by controlling the luminance by controlling the back light of a display device 101. In this case, this system is actualized by providing a setting storage memory 107 which stores parameter values corresponding to the power-saving level of the display device 101 and a power-saving control means which selects the power-saving level of the display device 101 according to input states from input devices 108 and 109 and information from a battery level detecting means 110 at the time of the power-saving process of the display device 101 and obtains and sets the parameter value corresponding to the power-saving level from the setting storage memory 107.