The surgical instrument has a tubular shaft (1) with a movable tool (2) at the distal end operated by a longitudinal moving pull and push rod (14) located in the shaft. The shaft is curved and the push and pull rod is formed as a flat bar (15) where it passes through the curved area of the shaft. The rod is made from a bendable elastic material and it has a series of axially separated circumferential slots (16) formed in it. The rod is contained within a sleeve which is formed by the inner wall of the shaft.
