Electrical apparatus for the generation, transmission, distribution and/or usage of electrical energy, said electrical apparatus comprising a housing enclosing an electrical apparatus interior space, at least a portion of the electrical apparatus interior space forming at least one insulation space, in which an electrical component is arranged and which contains an insulation medium surrounding the electrical component, the insulation medium comprising carbon dioxide, characterised by the insulation space comprising at least one insulation space compartment, in which an amount of adsorber (m ads) for reducing or eliminating an amount of water and further contaminants from the insulation medium is arranged, wherein m ads complies with the following formula: m ads ≤ 0.1 m CO 2 k ads, CO 2 with m CO2 being the amount of carbon dioxide present in the respective insulation space compartment at the time when placing the adsorber into the insulation space compartment; and k ads,CO2 being the adsorption capability of the adsorber towards carbon dioxide at the predetermined temperature T 0 at the time when placing the adsorber into the insulation space compartment, and wherein the insulation medium additionally comprises an organofluorine compound, and the amount of adsorber m ads arranged in the at least one insulation space compartment, in particular in each insulation space compartment, complies with the following formula (Ii): m ads ≥ m H 2 O k ads, H 2 O + ∑ i = 1 n m dp i k ads, dp i with m H2O being the amount of water present in the respective insulation space compartment at the time when placing the adsorber into the insulation space compartment, k ads,H2O being the adsorption capability of the adsorber towards water at a predetermined temperature T 0 at the time when placing the adsorber into the insulation space compartment, m dpi being the amount of a respective decomposition product dp 1, dp 2,... dp n created in and/or released into the respective insulation space compartment between gas maintenance or gas replacement intervals, with i being an index for the i-th decomposition product, and k ads,dpi being the adsorption capability of the adsorber towards the respective i-th decomposition product dp 1, dp 2,... dp n at the predetermined temperature T 0, and at least one decomposition product is a decomposition product of the organofluorine compound. m CO2 being the amount of carbon dioxide present in the respective insulation space compartment at the time when placing the adsorber into the insulation space compartment; and k ads,CO2 being the adsorption capability of the adsorber towards carbon dioxide at the predetermined temperature T 0 at the time when placing the adsorber into the insulation space compartment, and m H2O being the amount of water present in the respective insulation space compartment at the time when placing the adsorber into the insulation space compartment, k ads,H2O being the adsorption capability of the adsorber towards water at a predetermined temperature T 0 at the time when placing the adsorber into the insulation space compartment, m dpi being the amount of a respective decomposition product dp 1, dp 2,... dp n created in and/or released into the respective insulation space compartment between gas maintenance or gas replacement intervals, with i being an index for the i-th decomposition product, and k ads,dpi being the adsorption capability of the adsorber towards the respective i-th decomposition product dp 1, dp 2,... dp n at the predetermined temperature T 0, and at least one decomposition product is a decomposition product of the organofluorine compound.