This paper reports the results of an experimental investigation on the thermophysical, chemical and dielectric properties of three varieties of date palm wood (Phoenix dactylifera L) from Biskra oasis in Algeria. The goal is to use this natural material in the manufacture of thermal insulation for buildings. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis of the date palm wood were investigated to characterize the microstructure and the chemical composition of the samples. A simultaneous determination of the thermal conductivity and the diffusivity was achieved using a periodic method. The relative permittivity was obtained from capacitance measurements performed at room temperature. The results have shown that the surfaces of the samples are irregular with many filaments, impurities, cells and pores. The effect of the fibers orientation was significant on the relative permittivity when compared to the thermal conductivity of the date palm wood. Furthermore, the thermal conductivity measured in vacuum and at atmospheric pressure showed that the material remains, in both cases, with good properties. This result was confirmed comparing to the thermal conductivity of other natural insulating materials. Hence the date palm wood is a good candidate for the development of efficient and safe insulating materials. (C) 2010 Elsevier B.V. All rights reserved.