The reflection of electromagnetic plane waves incident obliquely upon a semibounded, maxwellian plasma is investigated based on the kinetic theory. The perturbed velocity distribution function is assumed to satisfy the boundary condition of a diffuse scattering at the surface of the plasma. The numerical results of the reflection coefficients are presented for both cases of incidence of TM and TE waves. It is shown that as the temperature of plasma increases, the reflected energy from the diffuse scattering boundary is significantly reduced, especially within the frequency range of usual total reflection. This phenomenon is discussed at some length and is brought out to be closely related to a collisionless energy absorption by the surface charges which couple resonantly to the incident wave.