1. Thermocouples made of high-melting compounds of transition metals (carbides, borides, nitrides and silicides) make it possible to measure temperatures under more exacting conditions and have a higher thermal-emf than the existing metal high-temperature thermocouples; moreover, they are as accurate as metal thermocouples. 2. Changes in the thermal-emf of high-melting thermocouples decrease with a rising operation time, thus making it advisable and necessaryto submit them to stabilizing annealing; by using thermocouple materials with close chemical tolerances, standardizing their production and annealing, it becomes possible to produce thermocouples with standard calibrations. 3. The results published in this article are not final, since they were obtained on several tens of thermocouples made under laboratory conditions.