Abstract: An endoscope system has a light source configured to emit first illumination light and second illumination light; an optical fiber configured to transmit the first and second illumination light to the tip portion of a scope; and scanner configured to spirally scan a target area with the illumination light by vibrating the tip portion of said optical fiber. The endoscope system further has an illumination controller that switches between the first illumination light and the second illumination light in accordance to a scanning position so as to mix areas illuminated by first illumination light with areas illuminated by second illumination light; and an image generator configured to detect pixel signals on the basis of light reflected from the target area at a given sampling rate and to form an observation image from the detected pixel signals.