The present invention relates to a membrane (12) for a pressure dome (10) suitable for cooperation with a pressure sensor (22). The membrane comprises a resilient circular wall (120) suitable for closing one side of the pressure dome (10) so as to define a partition between the inside of the pressure dome and the outside and a circular rim (124) suitable for being joined to a main body (16) of the pressure dome. The membrane is characterized in that the resilient circular wall, when there is no difference between the pressures acting respectively on the inner surface (121) and on the outer surface (122), has an outwardly convex form. The invention also relates to a pressure dome comprising the membrane.