An endoscope system has an oxygen saturation calculation unit that calculates the oxygen saturation of an observation object, and includes an image acquisition unit that acquires a preliminarily captured image that is an image of the observation object, a correction unit that corrects an LUT that the oxygen saturation calculation unit uses for the calculation of the oxygen saturation, using the preliminarily captured image, a determination unit that determines a success or failure of the correction, and a warning unit that performs warning in a case where a determination result obtained by the determination unit is a failure.
