An endoscope system of the present invention includes a control part has a computation part which computes the radius of curvature of the central axis of the instrument channel when the input signal is received and, may generate the first driving signal according to a result of the computation part computing the radius of curvature so that a treatment instrument at which a rigid part is provided to be easily inserted into a channel while a view of an observation part is limited from deviating from an object to be treated, even when a radius of curvature of a bending part is small while the bending part is bent.
