A manipulator includes: an elongated body portion that can be inserted into a body； and an energy treatment mechanism provided at a distal end of the body portion. The energy treatment mechanism is provided with gripping pieces that can grip body tissue and an energy applying part configured to apply energy to the body tissue gripped by the gripping pieces. The body portion is provided with an energy transfer part configured to transfer energy to the energy applying part and a force amplifying mechanism configured to amplify gripping force of the gripping pieces.
