The present medical system has an external tube, a treatment tool channel, a treatment tool inserted into the treatment tool channel, and a holding tool provided on the external tube, wherein the holding tool has a grip part for holding the treatment tool and a joint for moving the grip part with respect to the external tube, and the treatment tool has a treatment part that performs treatment for a site to be treated, a flexible tube part provided at an end thereof with the treatment part and inserted into the treatment tool channel, and a ring part provided on at least one of the treatment part and the flexible tube part and gripped by the grip part.