The disclosed technology is directed to a rotating mechanism for a treatment tool or grasping forceps which comprises a rotating member having respective first and second ends. The first end is supported on a distal end of an elongated member for rotation about a longitudinal axis of the elongated member. The grasping forceps is attached to the second end of the rotating member. An axial force transmitting member is configured to be disposed along the elongated member for transmitting axial forces. An actuating member is attached to a distal end of the axial force transmitting member. A converting mechanism is used for converting the linear movement to the rotary movement of the actuating member along the longitudinal axis. The linear movement of the actuating member is not transmitted to the rotating member and the rotary movement of the actuating member about the longitudinal axis is transmitted to the rotating member.
