A pressure or force sensor has a sensor housing, a measuring element in the housing, and a sensor membrane. The membrane is delimited by an inner edge and an outer edge, which is connected in a pressure-resistant manner to the sensor housing. The inner edge transitions in a pressure-resistant manner into a movable plunger, the travel of which can be detected by the measuring element. The membrane has one or more elastic regions between the outer edge and the inner edge, each region having a thinnest point, wherein the material thickness inside the elastic region increases steadily on both sides of this thinnest point. The cross-section of the membrane has an arched shape in each elastic region, and the arched shape has a convex outer and concave inner contour relative to the arch orientation.