Abstract: A three-phase combined type gas insulated bus is disclosed which comprises at least one eddy current conductor for passing the eddy current caused secondarily by the current flowing in high voltage conductors, thus solving the problem of a newly-found phenomenon that the temperature of a sealed casing increases by the flow of the eddy current. This eddy current conductor is made of such a material of good electrical conductivity as aluminum or copper. Even in the case where the sealed casing is reduced in diameter to such an extent as to pose a problem of temperature increase by the eddy current flow, the eddy current is reduced or completely eliminated in the best case, so that the sealed casing can be made of a low cost soft steel.