Gas-insulated electrical switchgear for medium and high voltage electrical distribution networks comprising: - a first enclosure insulated in a gas and provided with at least one electrical connection means and at least one mechanical connection means ; - an operating means integrated inside a second enclosure , arranged between at least one bar of a main circuit and at least one branch bar , said operating means comprising a gas breaking switch, said second enclosure equipped with the operating means being comprised inside the first enclosure ; - an actuating element configured to actuate the operating means that performs the functions of breaking, making, disconnecting, and grounding; and - an operating mechanism to cause actuation of the actuating element ; - wherein the mechanical connection means couples the operating mechanism to the first enclosure ; the gas-insulated electrical switchgear being characterized in that : - the switchgear further comprises a plurality of covers that incorporate inside, concentrically, the bars of the main circuit and the branch bars , the medium between the bars and the cover being a gas; - the first enclosure comprises inside the covers that incorporate the bars of the main circuit and branch bars ; - the covers are made of an electrically non-conductive material and comprise hollow parts, having cylindrical geometry, which are coupled to each other by means of at least one first joining means ; and in that - the bars of the main circuit and the branch bars have a cylindrical geometry, and in that they further comprise at least one second joining means that allows joining between bars of the main circuit or joining between branch bars . - a first enclosure insulated in a gas and provided with at least one electrical connection means and at least one mechanical connection means ; - an operating means integrated inside a second enclosure , arranged between at least one bar of a main circuit and at least one branch bar , said operating means comprising a gas breaking switch, said second enclosure equipped with the operating means being comprised inside the first enclosure ; - an actuating element configured to actuate the operating means that performs the functions of breaking, making, disconnecting, and grounding; and - an operating mechanism to cause actuation of the actuating element ; - wherein the mechanical connection means couples the operating mechanism to the first enclosure ; - the switchgear further comprises a plurality of covers that incorporate inside, concentrically, the bars of the main circuit and the branch bars , the medium between the bars and the cover being a gas; - the first enclosure comprises inside the covers that incorporate the bars of the main circuit and branch bars ; - the covers are made of an electrically non-conductive material and comprise hollow parts, having cylindrical geometry, which are coupled to each other by means of at least one first joining means ; and in that - the bars of the main circuit and the branch bars have a cylindrical geometry, and in that they further comprise at least one second joining means that allows joining between bars of the main circuit or joining between branch bars . <EOS>