Provided is a surgical system capable of securing insulation between an endoscope and a treatment tool even when a movable body is formed of metal and an endoscope used in the surgical system. An endoscope having an insertion portion which can be inserted into a mantle tube and has a distal end, a proximal end and a longitudinal axis and which is anchored to a moving body by an endoscope holding portion, the endoscope being provided on the distal end side of the insertion portion A second insertion portion provided on the proximal end side of the first insertion portion and having an outer diameter larger than that of the first insertion portion, and a second insertion portion provided on the proximal end side And a to-be-held portion which is held by the endoscope holding portion and is formed of an insulating member having at least a surface having an insulating property.移動体を金属で形成した場合でも内視鏡と処置具との絶縁を確保することができる外科システム及びこの外科システムに用いられる内視鏡を提供する。外套管に挿入可能でかつ先端と基端と長手軸とを有する挿入部を有し、内視鏡保持部により移動体に係止される内視鏡であって、挿入部の先端側に設けられた第1の挿入部と、第1の挿入部の基端側に設けられ第1の挿入部よりも外径の大きい第2の挿入部と、第2の挿入部の先端から基端側に向かって設けられ内視鏡保持部により保持される被保持部であって、少なくとも表面が絶縁性を有する絶縁性部材で形成された被保持部と、を有する。
