Abstract: A circuit breaker for detecting overload is disclosed. The circuit breaker detects an overload condition electrically without using bimetal. The circuit breaker for detecting overload includes an arc fault detector and a discharge controller. If arc fault occurs, the discharge controller discharges voltage charged in a capacitor. Therefore, the circuit breaker does not trip the circuit when arc fault occurs although high current flows on a conductor. Further, the circuit breaker for detecting overload includes a charging time constant controller so that charging time is varied according to current flowing on the conductor.