The (111) facet faces on the seed cone of the  silicon single crystals grown by MCZ and CZ methods were characterized on an atomic scale by using X-ray CTR scattering. The natural (111) facet face of the MCZ single crystal was found to have a roughness of about three layers. This roughness is only very slightly inferior in comparison with that of the mechano-chemically polished (111) surface of a silicon wafer which has a roughness of two layers and is the flattest surface we have ever investigated. However, the (111) facet face of the usual CZ single crystal was so poor that the flatness could not be estimated. The effect of magnetic field on the crystal growth is discussed on the basis of these facts.