Many attempts have been communicated so far to increase solar cell efficiencies, among them using randomly or regularly rough surfaces of active layers of solar cells. One of successful representatives of this kind is the so-called black silicon (b-Si). In this paper we report angular and polarization reflectance properties of b-Si samples prepared via electrochemical etching in HF:MeOH solution supported by external electric field. As different angular response of resulting rough Si-air interface to sunlight can be anticipated, the angle-and polarization resolved reflectance measurements of b-Si are recorded and correlated to the simulation results considering surface roughness of the samples and graded Si-air effective medium.