A gas-insulated electric apparatus which connects a gas insulation bus line (X, Y) and a feeder through a gas insulation breaker, wherein the gas-insulated electric apparatus comprises: - a vertically-arranged gas insulation main tank (GIMT) which incorporates a vertically-arranged gas insulation breaker therein; - a first gas insulation branch pipe (GIBT1) which is connected with one side of an upper portion of the gas insulation main tank (GIMT) while making a substantially right angle with the extending direction of the gas insulation main tank (GIMT) and pulls out a feeder from a movable side of the gas insulation breaker; - a second gas insulation branch pipe (GIBT2) which is connected with one side of a lower portion of the gas insulation main tank (GIMT) while making a substantially right angle with the extending direction of the gas insulation main tank (GIMT) and connects a fixed side of the gas insulation breaker to the gas insulation bus line; - a breaker manipulator which is arranged on an upper side in the extending direction of the gas insulation main tank (GIMT); - a feeder-side current transformer which is incorporated in the first gas insulation branch pipe (GIBT1); - a voltage transformer which is arranged on the first gas insulation branch pipe (GIBT1) in a state that the voltage transformer is positioned above the first gas insulation branch pipe (GIBT1) and uses the feeder as a primary conductor; wherein a vertically-arranged cable head which extends in parallel to the gas insulation main tank (GIMT) and pulls the feeder to the outside is arranged below the first gas insulation branch pipe (GIBT1); wherein the second gas insulation branch pipe (GIBT2) and the gas insulation bus line (X, Y) are arranged inside of a space surrounded by the gas insulation main tank (GIMT), the first gas insulation branch pipe (GIBT1) and the cable head; characterised in that the gas-insulated electric apparatus comprises an arrestor which is arranged on the first gas insulation branch pipe (GIBT1) in a state that the arrestor is positionned above the first gas insulated branch pipe (GIBT1) and is connected with the feeder; and the height of the gas-insulated electric apparatus at the upper end of each of the breaker manipulator, the voltage transformer and the arrestor is substantially the same. - a vertically-arranged gas insulation main tank (GIMT) which incorporates a vertically-arranged gas insulation breaker therein; - a first gas insulation branch pipe (GIBT1) which is connected with one side of an upper portion of the gas insulation main tank (GIMT) while making a substantially right angle with the extending direction of the gas insulation main tank (GIMT) and pulls out a feeder from a movable side of the gas insulation breaker; - a second gas insulation branch pipe (GIBT2) which is connected with one side of a lower portion of the gas insulation main tank (GIMT) while making a substantially right angle with the extending direction of the gas insulation main tank (GIMT) and connects a fixed side of the gas insulation breaker to the gas insulation bus line; - a breaker manipulator which is arranged on an upper side in the extending direction of the gas insulation main tank (GIMT); - a feeder-side current transformer which is incorporated in the first gas insulation branch pipe (GIBT1); - a voltage transformer which is arranged on the first gas insulation branch pipe (GIBT1) in a state that the voltage transformer is positioned above the first gas insulation branch pipe (GIBT1) and uses the feeder as a primary conductor; wherein a vertically-arranged cable head which extends in parallel to the gas insulation main tank (GIMT) and pulls the feeder to the outside is arranged below the first gas insulation branch pipe (GIBT1);