An endoscope system 10 includes an image acquiring unit 54 that acquires a first image and a second image, the first image being obtained by using first illumination light, the second image being obtained by using second illumination light at a different timing from the first image; a halation-region detecting unit 74 that detects a halation region; a calculated-image generating unit 73 that performs calculation by using the first image and the second image and that generates a calculated image; a display-image generating unit 77 that generates a display image in which a tone reflects the calculated image; and a tone changing unit 75 that changes the tone of the halation region in the display image.