PURPOSE: To contrive communication valves and feed or exhaust valves not to be operated in error, by setting an operating board with set specified circuit conditions, and by switch-controlling the communication valves and the feed or exhaust valves with the switching command signal of the operating board.

CONSTITUTION: A gas-insulated apparatus divided by insulating spacers 7∼10 is provided with an operating board 20 with set specified circuit conditions, and the input of the state of the gas-insulated apparatus to the board 20 is provided. Then, by ON-command from the operating board 20, communication valves 11∼16 communicating in the gas-insulated apparatus are to be ON- operated. Besides, when the ON-state of the communication valves 11∼16 and the specified circuit conditions are regulated, then feed or exhaust valves 17∼19 are to be OFF-operated by OFF-command from the operating board 20. As a result, the valves are not operated in error, and reliability can be improved.