Luminance levels of a backlight 3 corresponding to gradations of a display image are registered as reference luminance values to a table 5a, signal levels of a drive signal to an LED driver 4 corresponding to reference luminance values are registered as luminance setting values to a table 6a, and values to correct a drive level of a liquid-crystal panel corresponding to gradations of the display image are registered as gamma correction values to a table 7a. According to the gradation of an image to be displayed, a signal level of the drive signal corresponding to the reference luminance value attained from the table 5a is obtained from the table 6a, to thereby drive the LED driver 4; and an LCD driver 2 is driven by a value obtained through correction by the gamma correction value obtained from the table 7a, to thereby display an image.