An endoscope system includes an insertion section, a bending portion provided in the insertion section, including a distal side and a proximal side, and deformable into an arcuate shape by bending in at least one predetermined direction, a distal-side bending portion, a proximal-side bending portion, a first variable stiffness section provided in the distal-side bending portion and configured to change a stiffness of the distal-side bending portion, a second variable stiffness section provided in the proximal-side bending portion and configured to change a stiffness of the proximal-side bending portion, and a controller for performing control to make a stiffness of the first variable stiffness section higher than a stiffness of the second variable stiffness section.
