The electric double layer of the (0001) face of a cadmium single crystal grown electrolytically in a Teflon capillary has been studied in a solution of NaF. A value of −0.99 ± 0.01 V (vs. SCE) was obtained for the zero charge potential (pzc). This value is compared with literature data for other cadmium faces and polycrystalline cadmium. It is shown that the pzc is practically independent of the crystallographic orientation. The capacity of the inner layer of the (0001) cadmium face is calculated and compared with that of mercury and of separate silver faces. It is concluded that the hydrophilirity of the (0001) face of cadmium is similar to that of mercury and much lower than that of the (111) and (100) faces of silver.