The influence of the 'shunting effect' of the near-surface region of the spatial charge by the spatial charge localized in a vacuum spacing, field electron emitter-anode, and the changes of its configuration under the action of the controlling magnetic field on emission characteristics of metallic cathodes have been theoretically analyzed. As a result of the numerical experiment we have obtained: the current-voltage dependences of the field emission diode with the tungsten cathode and the distribution of the potential in the diode in the presence of the transversal magnetic field.