A treatment instrument includes a first treatment portion including a first member with a first contact surface and a second member with a second contact surface; a movement mechanism to switch between a closed position where the first and second contact surfaces are close to each other and an open position where the first and second contact surfaces are separated each other; and a second treatment portion juxtaposed to the first treatment portion. A distal end of the second treatment portion is located at a distal side in the longitudinal axis than a distal end of the first treatment portion on the closed position.