The invention relates to a high-temperature sensor, which can be used at temperatures of at least 600° C. and comprises a metallic protective tube and a measuring resistance that is surrounded by a ceramic powder. The measuring resistance is connected to the electric cable by means of stress-relieved measuring resistance connecting wires and internal conductors. The latter are provided with a solid and/or flexible insulation consisting of a ceramic material. The measuring resistance and the internal conductors are arranged in a metallic protective tube, which narrows in the vicinity of the measuring resistance. The ceramic powder contains admixtures of oxygen-giving oxide compounds.