A treatment instrument (1) includes a grip (110) and a handle (160). The grip (110) is provided in an operation unit (100). The grip (110) includes a first surface (111) and a second surface (112) provided back to back. The handle (160) provided in the operation unit (100) on a distal end side of the grip (110). The handle (160) moves to the distal end side and the proximal end side relative to the grip (110). At least one of the first surface (111) and the second surface (112) is provided with a protrusion (121, 122).
