The present invention provides a gas-insulated electric apparatus which includes: a vertically-arranged gas insulation main tank; a first gas insulation branch pipe connected to and making right angle with the gas insulation main tank; a second gas insulation branch pipe connected to and making right angle with the gas insulation main tank; a breaker manipulator which is arranged on an upper side of the main tank, a feeder-side current transformer which is incorporated in the first gas insulation branch pipe; a voltage transformer arranged on the first gas insulation branch pipe; and an arrestor arranged on the first gas insulation branch pipe and connected with the feeder.