An endoscopic treatment tool of the present invention includes: a sheath (3)； a stylet (5)； a main manipulation part (6) which is connected to a proximal end side of the sheath (3) and the main manipulation part operates the stylet (5)； an auxiliary manipulation part (7) which is disposed to be separate from the main manipulation part (6) and the auxiliary manipulation part allows the stylet (5) to perform a helical motion； and a manipulation transmission member (8) which is made of a flexible member, the manipulation transmission member connecting the auxiliary manipulation part (7) to the main manipulation part (6), and the manipulation transmission member transmitting a manipulation input by the auxiliary manipulation part (7) with respect to the main manipulation part (6). The main manipulation part (6) includes a first helical mechanism which outputs a helical motion to the stylet (5), the auxiliary manipulation part (7) includes a second helical mechanism which outputs a helical motion to the stylet (5), and the helical motion output from the second helical mechanism is transmitted to the first helical mechanism via the manipulation transmission member in a state in which the main manipulation part (6) and the auxiliary manipulation part (7) are connected to each other.
