Abstract: An encapsulated, compressed-gas-insulated, high-voltage switching installation is disclosed in which the circuit breaker is arranged horizontally in a pressure vessel having one end wall formed by a base plate to which are secured the interrupter units of the circuit breaker and all parts of the drive and arc extinguishing device, including the control unit and hydraulical accumulator. The base plate with the interrupter units and all parts of the drive and arc extinguishing device connected thereto can be moved as a structural unit on rollers connected to the base plate rolling on the installation ground or on a foundation, or lifted by a crane.