Provided is a spot detection device including an imager configured to capture a display panel displaying a first image of a first grayscale and a second image of a second grayscale different from the first grayscale and generate image data, and a spot detector configured to receive the image data from the imager in order to detect a spot. The image data includes first image data obtained by capturing the first image, second image data obtained by capturing the second image, and a plurality of third image data obtained by capturing portions of the first image.