A deaerating and degassing system for a power plant condenser, comprising a condensate collector and optionally an air cooler, whereby the deaerating and degassing system includes a suction aggregate and a suction line for a steam-inert gas mixture and the suction line connects the condenser or, in case an air cooler is present, the air cooler of the condenser, to the suction aggregate. In the suction line, there is a direct-contact condensation device, for example, a packing column or a tray contact apparatus, through which the steam-inert gas mixture can flow in direct contact in a countercurrent to the chilled condensate from the condensate collector.