A high-frequency treatment tool for an endoscope includes: a sheath formed of a material having an insulation property； a shaft-shaped member formed of a material having conductivity and inserted to advance and retract in the sheath； and an electrode having a conduit line formed to jet forward a fluid supplied into the sheath, and connected to a distal end section of the shaft-shaped member. The electrode has an outer circumferential surface electrically connected to a contacted tissue to perform treatment, and an inner circumferential surface of the conduit line that faces the fluid when the fluid is supplied. An arithmetic average roughness of the outer circumferential surface is larger than an arithmetic average roughness of the inner circumferential surface, and the arithmetic average roughness of the inner circumferential surface is 0.1 μm or less.
