An endoscope system includes a rigid endoscope including an optical system in a rigid insert section thereof, and a wiper sheath. The wiper sheath includes a wiper insert section receiving the insert section of the rigid endoscope, a wiper arranged on a distal end portion of the wiper insert section and enabled to be placed in contact with a distal-end face of the rigid endoscope received in the wiper insert section, and an operation unit, arranged at a proximal end portion of the wiper insert section, for switching the wiper between a contact state with the wiper placed to be in contact with the distal-end face of the rigid endoscope and a detached state with the wiper spaced apart from the distal-end face of the rigid endoscope, and for moving the wiper on and along the distal-end face of the rigid endoscope when the wiper is in the contact state.