Abstract: An immersion sensor for molten metals has an electrically conducting support pin, whose one end is mounted in a refractory mounting material, and whose other free end has a first coating of a reference material and on top of this a second coating of a solid electrolyte material. The support pin has a third coating of a refractory material in the area of its mounted end, and this third coating on the one side extends into the mounting material, and on the other side extends into the solid electrolyte material. In order to obtain a quick reading and a stable EMF-value, the solid electrolyte material covers at least the end area of refractory coating nearest the free end of the support pin. A process for the manufacture of an intermediate for the immersion sensor applies the various coating materials of the immersion sensor in the order given above.