An endoscope system includes a processor and displays a distribution image of living substance feature amounts obtained from an imaged image of a living tissue. The processor calculates the living substance feature amount in the living tissue, for example, an amount of hemoglobin and oxygen saturation of the hemoglobin using components of color image data of the living tissue illuminated with at least two lights, generates the feature amount distribution image illustrating a distribution of the living substance feature amounts, and controls display of the feature amount distribution image in order to display the generated feature amount distribution image so as to be superimposed on the image of the living tissue.