The electrodes of these pressure or differential pressure sensors are formed using a technique other than silk-screen printing or sputtering: The pressure sensor (10) has a substrate (1) and a first major surface (11), a second major surface (12) and a circumferential surface (13. A plate-shaped electrode (14) of electrically conductive material is secured in a recess (15) in the major surface (11) in a high-pressure-resistant and high-vacuum-tight manner by a joining material (16). A through connection (17) is provided from the electrode (14) through the substrate (1) to the major surface (12) or the circumferential surface (13). A diaphragm (2) of ceramic, glass, or single-crystal material is attached to the substrate (1) outside the recess (15) along a joint (18) by a joining material (26), and forms itself a further electrode or is covered, on a surface facing the electrode (14), with a further electrode (24) which is contacted through the joint (18). Substrate and diaphragm consist of a ceramic, glass, or single-crystal material. Respective differential pressure sensors have either a common central diaphragm and two substrates or a common substrate and two diaphragms.