A medical system includes: a treatment instrument having an insertion portion configured by an exterior member, and an insertion member that is inserted into the exterior member and is longer than the exterior member an insertion portion inserting/pulling-out device to transmit a driving force to the exterior member or the insertion member configuring the insertion portion of the treatment instrument, the insertion portion inserting/pulling-out device advancing/retreating at least one of the exterior member and the insertion member and a driving force non-transmitting portion provided to the insertion member, the driving force non-transmitting portion preventing a driving force of the insertion portion inserting/pulling-out device from being transmitted to the exterior member when the insertion member is moved by a predetermined distance.
