Provided is a high-frequency treatment tool including a cylindrical sheath, an electrode member that is made to protrude and be retracted with respect to a distal-end portion of the sheath, and a liquid-feeding unit for feeding a liquid toward the distal-end side inside a flow channel in the sheath, wherein a distal end of the electrode member is provided with a distal-end expanded portion that extends radially outward in a radiating manner and that has a base-end surface that is made to protrude and be retracted with respect to a distal-end portion of the sheath, wherein the sheath is provided with a restricting portion that restricts the movement of the electrode member toward the base-end side at a position at which a portion of the distal-end expanded portion is accommodated inside the sheath and an accommodating portion that can accommodate at least a portion of the distal-end expanded portion.
