GAS CIRCUIT BREAKER

PROBLEM TO BE SOLVED: To provide a gas circuit breaker in which reignition can be prevented between electrified contacts by suppressing electrical field relaxation effect by means of an electrical field relaxation shield immediately after opening of the pole of an arc contact, electrical field relaxation effect can be exhibited by moving the electrical field relaxation shield in the axial direction as opening of the pole of the arc contact progresses, and thereby small current interruption performance is ensured while suppressing increase in the pole opening speed of the arc contact.SOLUTION: An electrical field shield 41 is floating and operable in the direction of the central axis. It is configured to be energized by a coil spring 42 coupled to the proximal end, and to operate to the movable contactor 20 side in the direction of the central axis as the coil spring 42 is de-energized during the breaking operation.