[en] The problem of penetration and reflection of an electromagnetic wave polarized in the plane of the incidence is investigated for a collisional plasma half space. The perturbed plasma is treated by the use of the linearized Boltzmann equation. Equilibrium plasma has been assumed to be homogeneous and isotropic and fractionally accomodating boundary condition with specular and diffuse reflection has been employed. The reflection coefficient is also derived. (author)