The invention relates to an arc extinguishing chamber and a circuit breaker, A circuit breaker comprises an operating mechanism and an arc extinguishing chamber, the arc extinguishing chamber includesa switch structure, the switch structure comprises a movable contact and a stationary contact arranged in front of and in cooperation with each other, Arc-extinguishing chamber also includes an exhaust passage for divert that arc gas generated by the dynamic and static contacts to be disconnected, and the movable contact is located on the front side of the exhaust passage, An outlet of that rearside of the exhaust passage is provided with an impeller for bee driven to rotate by air blowing, the rotational center axis of the impeller extends in the front-rear direction and the rotational center axis of the impeller extends in the front-rear direction, in the working process of the circuit breaker of the invention, the high temperature arc gas flows from front side to back side in the exhaust passage, so that that impeller is driven to rotate, so that the heat energy of the arc gas is converted into the kinetic energy of the impeller, and the arc gas is sufficiently disturbed when passing through the impeller, so that the temperature of the arc gas is lowered, and the structure which can play a cooling role on the arc gas does not cause the increase of the whole cost of the circuitbreaker due to the loss of the operation work in the working process.