A surgical instrument includes an instrument shaft, two instrument branches that can be positioned relatively to one another in a working position and a rest position, a handle element on which an operating element is movably arranged for positioning the instrument branches, and a coupling mechanism having a translating unit that converts a movement of the operating element, non-linearly, into a relative movement of at least one of the two instrument branches. The coupling mechanism includes at least one bias element that biases the mechanism into the rest position and/or into the working position of the instrument branches.