Provided are: a hermetically-enclosed tank that is filled with insulating gas; a blocking unit that is provided within the hermetically-enclosed tank and is configured with a movable arc contact and a fixed arc contact opposing each other; a plurality of energizing units, within the hermetically-enclosed tank, that are provided around the blocking unit about its axial line as a center and located away from each other; and a fixed-side auxiliary conductor that is provided between a gas space which stores the energizing units and a gas space on the side of the fixed arc contact. A communication hole is formed on the fixed-side auxiliary conductor so as to communicate the gas space provided between the energizing units with the gas space.