Provided is a high-frequency treatment tool (1) that includes an elongated cylindrical sheath (2)； a straight bar-shaped electrode member (3) to which high-frequency current is to be supplied, the electrode member being disposed so as to be advancable and retractable in the sheath in a longitudinal axis direction； a distal end member (6) that is disposed at a distal end side of the sheath (2) and has a through hole (6a) through which the electrode member (3) is passed； and a liquid feeding means (5) that is connected to a proximal end of the sheath (2). The electrode member (3) includes an electrode distal end portion (3b) being provided at a distal end of the electrode member and radially extending in a radially outward direction, and a stopper portion (7) disposed at a proximal end side with respect to the distal end member (6) and substantially having the shape of a solid of revolution. The distal end member (6) has a tapered inner surface (6b) that abuts against the stopper portion (7) in the longitudinal axis direction when the electrode member (3) is maximally moved toward the distal end, the tapered inner surface narrowing toward the distal end. A recessed portion (9) that constitutes a channel (2a) through which the liquid can be distributed in a state in which the tapered inner surface (6b) and the stopper portion (7) abut against each other is formed in the tapered inner surface (6b) or the stopper portion (7).
