GAS-INSULATION SWITCH DEVICE

A gas-insulated switchgear which efficiently removes a remaining thermal gas to improve an insulation performance, and which is capable of easily accomplishing a current breaking duty required for a switchgear for a high voltage is provided. Inside a movable shield 23, with a piston 25a of an operation rod 25 being a partition wall, a compression chamber 30 and a suction chamber 31 are formed at a movable-contact-base-22 side and a movable-contact-21 side, respectively. The compression chamber 30 compresses an insulating gas in the compression chamber 30 by a movement of the piston 25a at the time of circuit opening operation, and sprays the insulating gas to an arc 40 produced between the fixed arcing contact 11 and the movable contact 21 via a communication hole 25c, a hollow portion 25b, and a ventilation hole 21a. The suction chamber 31 reduces the internal pressure by expanding an internal space by a movement of the piston 25a to suction a high-temperature gas due to the arc 40 through a clearance 31a between the movable contact 21 and the movable shield 23.