Abstract: A capacitor bank for use in high voltage electric plants such as series or shunt capacitors or in filter circuits for high voltage direct current plants. The capacitor bank comprises a number of capacitor units in a closed tank containing a gas for electric insulation and for regulating the temperature in the tank. Each of the capacitor units comprise a closed casing provided with bushings for current inlet and outlet, a number of capacitor elements connected together inside the casing and the casing is filled with an insulating fluid. The capacitor units are mounted in a rack of insulating material constituting the sole support for the capacitor units as well as electrically insulating the capacitor units from one another. The rack includes guide members for at least part of the gas circulating in the tank to achieve substantially the same temperature in the individual capacitor units.