A medical instrument for manipulating, in particular retracting tissue or an organ in the human or animal body, comprises an elongated shaft having a distal portion introducible into the body, and at least one working element arranged at a distal end portion of the shaft for manipulating the tissue or organ. The at least one working element comprises at least one magnetically acting element producing a magnetic field for manipulating the tissue or organ. A method for manipulating, in particular retracting tissue or an organ uses the instrument.