The aim of this paper is the characterization of materials submitted to high temperatures (up to 3000 °C). In this field, some mechanical tests are available the experiments involve a lot of critical measurements which depends on the applied strength and on the temperature. An alternative solution is an ultrasonic method which advantages are a non destructive mechanism and a possible determination of the elastic moduli for a very weak strength to deformation ratio [1]. In that field, to determine the material behavior at high temperatures by a non destructive method, we propose three different devices. Two of them are based on contact measurement with delay-lines working up to 1000 °C and up to 3000°C respectively. The last device, which is composed of a laser excitation and an interferometric detection, constitutes a non contact method especially useful for materials submitted to temperature neir their melting point. This paper is divided into three parts. The first one presents the principle of the elastic moduli measurement. The second one describes the different experimental set-up and the last part gives some results on metallic and organic samples.