The control of energy in the industrial sector and the reduction of consumption in the building sector will be key elements in the energy transition. In order to achieve these objectives it is necessary to use, in the first case, materials with energy performance adapted to their use and, in the second case, insulators, or rather super-insulators. In both cases, a perfect knowledge of their thermal properties will be a requirement for optimal success.This book enables the reader to choose the measurement method best suited to the material they are characterizing, and provides all of the informationrequired in order to implement it with maximum precision. This work is intended to be accessible to anyone who needs to measure the thermal properties of a material, regardless of whether they are a thermal engineer.