An endoscope system includes an endoscope, an illumination portion, a light adjustment portion, an insertion channel configured to allow insertion of a laser probe capable of radiating an aiming monochromatic laser beam, a gain control portion, a halation detection portion, and a control portion, and in a case that halation by the aiming monochromatic laser beam is detected in the halation detection portion, the control portion controls the light adjustment portion to adjust the illumination light and controls the gain control portion to control the gain.
