An endoscope system capable of setting the optimal balance of light source wavelengths in accordance with a diagnosis purpose is provided. An endoscope system includes a diagnosis purpose acquisition unit, a plurality of light sources with different light emission wavelengths, a light quantity ratio storage unit, a light quantity ratio selection unit, and a light source control unit. The diagnosis purpose acquisition unit acquires a diagnosis purpose. The light quantity ratio storage unit stores correspondence between the diagnosis purpose and a plurality of light quantity ratios with different balances of respective emission light quantities of the plurality of light sources. The light quantity ratio selection unit refers to the light quantity ratio storage unit and selects the light quantity ratio that is used for the acquired diagnosis purpose. The light source control unit controls the plurality of light sources to emit illumination light with the selected light quantity ratio.
