A medical instrument for grasping tissue comprises a shaft (12), a working element arrangement (28) arranged at a distal end (26) of the shaft (12) and having a first working element (30) and a second working element (32) configured to cooperate with one another for grasping tissue. At least the first working element (30) is movable, so that the working element arrangement (28) can be closed and opened. A magnet arrangement (50) is coupled to the working element arrangement (28) for closing and opening the working element arrangement via attracting and repulsive magnetic forces, respectively. The magnet arrangement (50) has at least three magnets (52a-52e, 56a-56d). According to a first aspect, at least two first magnets (52a-e) are arranged on one of the first and second working elements (30, 32) in series along a longitudinal axis (38, 54) thereof and have antiparallel magnetic polarities with respect to one another, and at least one second magnet (56a-56d) is arranged on the other of the first and second working elements (30, 32) and has a magnetic polarity parallel to one of the at least two first magnets (52a-52e), wherein the first magnets (52a-52e) and/or the second magnet (56a-56d) are/is displaceable in direction of the longitudinal axis (38, 54) of the first or second working elements (30, 32) such that the at least one second magnet (56a-56d) can be selectively paired with one of the first magnets (52a-52e) to obtain the magnetic attractive force or the repulsive force.
