Gas circuit breaker

A gas circuit breaker comprising:

• a sealed container filled with an arc-extinguishing gas;
• a first contact part and a second contact part provided to come into contact with each other and be separated from each other in the sealed container in a predetermined direction and separated from each other in an open electrode state while coming into contact with each other in a closed electrode state;
• an operation mechanism connected to the first contact part and configured to separate the first contact part and the second contact part from the closed electrode state to the open electrode state;
• an insulating nozzle formed in a tubular shape and configured to surround arc discharge generated between the first contact part and the second contact part in the open electrode state while being displaced in conjunction with the first contact part in a separation process of the first contact part and the second contact part;
• a pressure accumulator configured to discharge the arc-extinguishing gas to a flow path in the insulating nozzle to perform blasting with respect to the arc discharge while accumulating a pressure of the arc-extinguishing gas;
• and
• an electric field shield attached to the insulating nozzle, having a floating potential in a period of at least part of the separation process and electrically connected to the second contact part such that the electric field shield has the same potential in a completely open electrode state in which separation between the first contact part and the second contact part is terminated.