  The methodical properties of the original difference method for the search of
the anisotropy at the knee region of the primary cosmic radiation energy
spectrum are analyzed. The main feature of the suggested method is a study of
the difference in the EAS characteristics in different directions but not their
intensity. It is shown that the method is stable to the random experimental
errors and allows to separate the anomalies related to the laboratory
coordinate system from the anomalies in the celestial coordinates. The method
uses multiple scattering of the charge particles in the Galaxy magnetic fields
to study the whole celestial sphere including the regions outside of the line
of sight of the installation.
