Provided is a treatment tool 20 configured so that no induction current flows through a manipulation wire 25 of a manipulation part 24 manipulated by an operator. The treatment tool 20 includes: the manipulation part 24 that is manipulated by an operator an insertion part 22 that is elongated from the manipulation part 24 and is inserted into a body of a subject and the manipulation wire 25 that passes through the insertion part 22 to transmit manipulation at the manipulation part 24 to a treatment part 21 on a forward-end side of the insertion part 22. The manipulation wire 25 includes a first wire 26 having one end connected to the treatment part 21, to which AC magnetic field or AC electrical field is applied, and a second wire 28 having one end connected to the manipulation part 24 and the other end that is connected to the first wire 26 but is insulated electrically from the first wire 26.
