One of the most important problems in the development of advanced products of aerospace engineering and highly efficient power plants is to make high-temperature structural, heat-shielding and heat-insulating materials with extremely high operating temperatures of 2000--2500 °C. Even for prototype models, it is necessary to make a qualitative breakthrough in the field of materials science and the production of new high-temperature composite and heat-insulating materials which provide thermal protection and the permissible temperature conditions of structural elements at high temperatures. The practical application of the developed materials requires an evaluation of the whole body of their physicomechanical, optical, and thermophysical characteristics, which can only be done in experimental studies. We developed the design of the experimental setup and the methodology for the approximate evaluation of the thermophysical characteristics of highly porous heat-insulating materials at temperatures up to 2000 °C. A propane / oxygen or acetylene / oxygen multi-nozzle torch serves as a heating source for samples with a characteristic size of up to 50 × 50 mm. The paper substantiates the methodology for processing the measurement results in order to determine the thermophysical characteristics, and gives the results of a study of the thermal conductivity of highly porous zirconium oxide-based material