In a housing (1) for an apparatus having a movable member (5, 6) which is led through the housing wall in a sealed manner, a device for preventing the ambient atmosphere from penetrating into the housing interior (3) comprises a flexible wall region (11) which can be adjusted in a temperature-dependent manner such that the temperature-dependent change in volume of the housing contents does not cause any pressure difference with respect to the ambient atmosphere (10). <IMAGE>
