An image display device includes: a display part 4 that displays a video image based on an input signal; a video image adjusting part 33 for adjusting a parameter of the video image; and a region selecting part 31 for selecting a region in the video image, with respect to which an adjustment of the parameter is performed. The display part is capable of composing, based a video image in the selected region, a first video image 31a before the adjustment of the parameter and a second video image 31b to be used for the adjustment, displaying the first video image and the second video image above and below each other or side by side, and displaying either of the first video image and the second video image upside down or in a mirror-reversed manner. By operating the chroma adjusting bar 34, the hue adjusting bar 35, the luminance adjusting bar 36 of the video image adjusting part 33 (image adjustment parameter display screen), the second video image 31b is varied, and when a desired video image is obtained, the image is fixed, so that contents of the adjustment are reflected throughout the whole video image. Since the first video image or the second video image is displayed upside down or in a mirror-reversed manner, an influence of the human visual characteristics is eliminated, thereby enabling a precise image quality adjustment.