With respect to a forceps type treatment instrument including an ultrasound probe that protrudes from a treatment instrument main body at a position separated to a distal end side from a shaft portion, and a jaw that is displaceable between a closed state and an opened state by being linked with swing action of an clamp arm in a position separated to a distal end side from the shaft portion, stoppers are extendedly provided toward a clamp arm side from a treatment instrument main body side in a state in which edge portions at a distal end side are set to located at a distal end side from a locus of a proximal end of the jaw, and entry of a living body into a gap of the treatment instrument main body and the clamp arm is restricted.