A micro-structured reference element for use in a sensor having a substrate and a dielectric membrane. The reference element has an electrical property which changes its value on the basis of temperature. The reference element is arranged with respect to the substrate so that the reference element is (i) electrically insulated from the substrate, and (ii) thermally coupled to the substrate. The reference element is arranged on the underside of the dielectric membrane. The reference element and side walls of the substrate define a circumferential cavern therebetween, which is also bounded by the dielectric membrane, arranged between them. The dielectric membrane is connected to the substrate. A surface area of the reference element which is covered by the dielectric membrane is greater than or equal to 10% and less than or equal to 100% of the possible coverable surface area. A surface of the cavern which is covered by the dielectric membrane is greater than or equal to 50% and less than or equal to 100% of the possible coverable surface. An edge of the reference element which faces the dielectric membrane has greater than or equal to 50% and less than or equal to 100% of its extent contacted by the dielectric membrane. Sections of the side walls of the cavern which face the dielectric membrane have greater than or equal to 50% and less than or equal to 100% of the possible size contacted by the dielectric membrane.