Circuit breaker

The utility model discloses a circuit breaker. The circuit breaker of the utility model comprises a housing and a plurality of cavities formed in the housing. The plurality of cavities comprise an arcextinguishing cavity used for installing an arc extinguishing chamber, a tripping cavity used for installing a tripping part, and an accessory cavity used for installing accessories. A deionization device for separating the arc extinguish chamber from the tripping chamber is arranged between the arc extinguish chamber and the tripping chamber, and/or a deionization device for separating the arc extinguish chamber from the accessory chamber is arranged between the arc extinguish chamber and the accessory chamber. The internal space of the circuit breaker is divided into the tripping cavity, the accessory cavity for installing accessories and the like, and the arc extinguishing cavity for installing the arc extinguishing chamber is equally separated from the tripping cavity and the accessory cavity through the deio