The present paper deals with the propagation of millimeter wave through the layers of dielectric bodies. Theoretical investigation has been carried out to estimate the absorption loss (P_abs) in which the wave guide has been utilized. For simplicity of the problem each layers of the dielectric body has been considered as a wave guide and entire layers equated as a number of transmission lines in cascade. Consequently the equation for reflection coefficient and transmission coefficient has been developed. It will be further utilized for the evaluation of absorption loss as function of frequency and the particle density. The result has good agreement with theoretical value.