Abstract: A surgical instrument having at least two distal jaw parts each having a proximal part, an instrument holder for enabling a user to hold the surgical instrument, a pull-push rod connected to the jaw parts for pivotably moving the jaw parts such that the jaw parts are movable commonly and in opposite directions from one another, and a sliding block guide for guiding movement of the push-pull rod consisting of a circular arc-shaped groove foamed in the proximal part of each the jaw part. Each circular groove in each respective jaw part is displaced by 180.degree. from another circular groove in another jaw part. Each circular groove defining a virtual circle. At least two circular arc-shaped groove blocks are disposed on the instrument holder.