In a surgical tool, the treatment tool piece operating joint includes a first operating rotation member which is coupled to the moving member and is rotated around a predetermined rotation center a second operating rotation member which is coupled to the first operating rotation member so as to relatively rotate around a rotation center coaxial with the second bending rotary shaft in a rotation direction opposite to a rotation direction of the first operating rotation member or around a rotation center that is a position closer to the first bending rotary shaft than the second bending rotary shaft in a rotation direction opposite to a rotation direction of the first operating rotation member and a link which converts a rotational force of the second operating rotation member into the operation of the treatment tool piece.
