The present invention has an object to provide a gradation correcting apparatus for correcting the gradation of the white side of a video luminance signal.The gradation correcting apparatus is provided with a maximum value detector 101 for detecting a maximum value of a luminance signal S101, a white comparator 102 for comparing the luminance signal S101, a maximum luminance value S111 detected by the maximum value detector 101, and a first white threshold value S103, a white linear converter 103 for performing linear conversion on the luminance signal S101 on the basis of the maximum luminance value S111, the first white threshold value S103, and a second white threshold value S104, and a white controller 104 for correcting the luminance signal S101 on the basis of the result of the comparison in the white comparator 102, the output of the white linear converter 103, and the second white threshold value S104.