A contact force testing apparatus includes a measuring sensor that can be contacted with an electrical contact element and measures a contact force (F) of a contact with the electrical contact element of an electrical connector having a male component and a female component. The measuring sensor receives the contact force in a contact region with a piezoelectric pick-up. The measuring sensor includes a plurality of piezoelectric pick-ups that are spaced apart from one another by pick-up gaps. The measuring sensor has a protective sleeve that covers the piezoelectric pick-ups and the pick-up gaps in the contact region.