Monocrystalline tungsten and its alloys are of interest in the design and manufacture of high temperature facilities operating at high (up to 2500 degrees C) temperatures in vacuum under mechanical loads. This paper demonstrates advantages of using monocrystalline tungsten as a structural material in high-tech industry in comparison with poly-crystalline materials. The results of comparative studies of the thermophysical properties of polycrystalline and monocrystalline tungsten 4% tantalum alloy are presented. It is shown that monocrystalline tungsten based materials are more suitable for use under high temperatures and high mechanical stresses than polycrystalline. Use of mono crystalline tungsten as a structural material makes it possible to prolong the service life of modern technical facilities. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.