Provided is an endoscope system capable of improving luminance and an S/N ratio of a normal observation image that is obtained in a special observation mode.In a special observation mode, after first illumination light is radiated, some of a plurality of pixel rows of an imaging element are reset en bloc. Illumination light is switched to second illumination light, the second illumination light is radiated, and then, a turned-off state is reached. During this turn-off period, signal reading is sequentially performed from all pixel rows. An image processing unit generates a normal observation image on the basis of a first imaging signal without being subjected to resetting. Further, the image processing unit generates an oxygen saturation image on the basis of a second imaging signal read from the pixel row subjected to the resetting and exposed by only the second illumination light, and the first imaging signal.