To provide a gas insulated bus which efficiently implements work for connecting grounded tanks at a low cost and in a small space, surely prevents degradation of dielectric strength caused by impurities such as metal foreign objects, etc., and improves reliability of insulating.

The grounded tanks 1, 11 having the same shape and dimension are provided. Flanges 5, 5 are formed at ends of the grounded tanks 1, 11. Center conductors 2, 12 connected to each other are coaxially disposed in the grounded tanks 1, 11. A shield 4, which strides the flanges 5, 5 of the grounded tanks 1, 11, is mounted in an inner circumference of the grounded tank 1, 11.