Provided are a surgery system that can ensure insulation between an endoscope and a treatment tool even in a case where a movable body is formed of metal, and an endoscope used for this surgery system. The endoscope has an insertion part that is insertable into an overtube and has a distal end, a proximal end, and a longitudinal axis, and is locked to the movable body by an endoscope holding part. The endoscope has a first insertion part that is provided on a distal end side of the insertion part, a second insertion part that is provided on a proximal end side of the first insertion part and has an external diameter larger than that of the first insertion part, and a held part that is provided from a distal end of the second insertion part toward a proximal end side thereof, is held by the endoscope holding part, and has at least a surface formed of an insulating member having an insulation property.
