An endoscope system (10, 200, 300) comprises an LED light source unit (14), an image sensor (48, 304), an imaging distance calculator (65) and a light source controller (32, 210). The LED light source unit generates illumination light. The image sensor has a blue pixel (B), a green pixel (G), a red pixel (R) and a specific pixel (W) receiving at least light in a blue wavelength band and a green wavelength light, and images an observation object by reflected light of the illumination light from the observation object. The imaging distance calculator calculates an imaging distance that is a distance between the image sensor and the observation object. The light source controller controls the light source unit to increase a component of the blue wavelength band or the green wavelength band included in the illumination light according to the imaging distance.
