A treatment instrument for an endoscope having improved liquid delivery performance is provided. The treatment instrument for an endoscope comprises: a sheath (31) that is inserted in a body cavity from the tip side a cap member (32) which is disposed at the tip of the sheath (31), and in which a liquid delivery opening (34) used to deliver liquids through the sheath (31) is formed toward the front a rod-shaped electrode (41) that is supported by being inserted in the cap member (32) and a tip electrode (42) that extends radially from the leading edge of the rod-shaped electrode (41) in at least the front view. At least part of the liquid delivery opening (34) is exposed from the tip electrode (42) in the front view of the cap member (32).
