National Centre for Scientific Research “Demokritos” gained extensive know-how and capabilities on multi-purpose characterization of high-performance materials for extreme environments supporting material optimization in the intended application and overall performance improvement. The facilities and know-how have been generated for the characterization and development of fusion structural, high heat flux and functional materials, allowing for dozens of material properties to be accurately determined. Thanks to these remarkable performances, preliminary applications for materials used in aerospace applications have already been found. Material characterization in conjunction with know-how for innovative material development and material testing capabilities are now available for further use in applications where materials are exposed to extreme environments, like Nuclear, Aerospace, Energy systems, Automotive, Marine and Defence sectors.