A circuit interrupter includes a fixed terminal, a movable contactor, a moving mechanism, a squib, and accommodation. The fixed terminal includes a fixed contact. The movable contactor includes a movable contact connected to the fixed contact. The moving mechanism is configured to move the movable contactor from a closed position where the movable contact is connected to the fixed contact to an open position where the movable contact is separated from the fixed contact. The squib is configured to generate gas by combustion. The accommodation is for accommodating the fixed contact and the movable contactor. In the circuit interrupter, the gas is introduced into the accommodation.