A method is disclosed for operating a circuit breaker, the circuit breaker. The circuit breaker includes an operating lever, a latching mechanism and an electrical contact system with a movable contact and a fixed contact. The operating lever is movable into an ON-position and an OFF-position. Further, the operating lever is mechanically connected via the latching mechanism to the contact system such that when the operating lever is in its OFF-position, the contacts of the electrical contact system are opened and when the operating lever is in its ON-position, the contacts of the electrical contact system are closed. Further, such a circuit breaker is also disclosed.