A sensor (1) for capacitively measuring the distance to a stationary or passing object. The sensor has an electrode (2) that capacitively couples with the object and is formed from an electrically conductive ceramic material. The electrode is substantially surrounded by a housing (4) formed from an electrically non-conductive ceramic. The electrically conductive and electrically non-conductive ceramic materials are chosen to that they have the similar thermal expansion coefficients so that the sensor remains virtually stress free at high temperatures.