Abstract: The invention relates to a feed water degasifier comprising a degasifier (8) with a feed water tank (1) connected thereto, said components being integrated into the water/steam cycle of a solar thermal power station that has a heat transfer medium circuit with an associated water/steam cycle. The aim of the invention is to provide a solution, which in terms of the heating and control process provides a less complex way of supplying the degasifier with heating steam in comparison with prior art. To achieve this, at least one additional evaporator (11), which has a line connection (12) on the water side to the feed water region (5) of the feed water tank (1) and a line connection (13) on the steam side to the steam region (6) of the feed water tank (1), is allocated to the feed water tank (1).