Power supply unit, in particular for a sterilization device, comprising a housing, an electric system and an electric insulation system, wherein the electric insulation system comprises at least one insulation shield, wherein the electric system is located within the housing, and wherein the electric system has, during operation, zones that have different voltage distributions, wherein the housing comprises a plurality of areas, and wherein at least one area comprises the at least one insulation shield, wherein those areas which distance to a zone of the electric system which voltage distribution exceeds a first voltage threshold is below a minimum distance comprise at least one insulation shield.
