An air circuit breaker is provided wherein a rotational force is accurately discontinued at a movement completion time of assuming a connected position, a test position or a disconnected position by a breaker body in the process of withdrawing in and withdrawing out the breaker body from a cradle whereas a driving connection is performed if necessary, the breaker including a coupling device capable of being moved to a position where a withdraw-in and withdraw-out driving force generated by a manipulating handle is transmitted to a withdraw in and withdraw out apparatus and to a position where the withdraw-in and withdraw-out driving force is stopped of transmission.