A processor 4 includes: first to third matrix circuits 40, 46 that generate an image signal of normal light and an image signal of special light based on an output of a CCD 16 that picks up an image of returning light of light that is irradiated onto living tissue； a color discrimination circuit 47 that discriminates a color for respective pixels with respect to an image signal of the special light； and a color correction circuit 48 that, in an observation mode that uses special light, based on a discrimination result by the color discrimination circuit 47, performs color correction with respect to a color of the observation object other than the living tissue such that the color of the observation object is similar to a color thereof in an observation mode that uses the normal light.
