Abstract: A wire bonder comprises a bonding head with a rocker which is arranged on the bonding head and is rotatable about a horizontal axis. The rocker comprises at least three bores into which a piezoelectric element each is inserted, which element is used either as a sensor or as a piezoelectric drive in order to move a horn which is fastened to a body relative to the rocker. The body is tightly screwed onto the rocker by means of at least three screws, with at least two screws being tightly screwed in a resilient way. The body is pressed against the piezoelectric elements. A membrane is preferably arranged between the rocker and the body, which membrane prevents that shearing forces can act upon the piezoelectric elements.