The gas sensor has a selectively permeable membrane which is composed of silicon material and is provided with a heating device on the outside. The membrane closes an evacuated housing which contains a pressure sensor. When evacuating the area surrounding the housing, the heat dissipation is changed as a result of the quick change in the total pressure of the surrounding air, with the result that signal drift arises despite temperature regulation of the membrane. The disclosure provides at least one second heating device whose temperature is regulated independently of the first heating device. As a result, the membrane temperature is highly constant even in the case of severely changing total pressure in the housing.