A method has been developed for calculating the parameters of electron beam necessary for remote elemental analysis of lunar surface rocks using characteristic X-ray emission excited by electrons of the beam in a surface layer. It is shown that creation of a set of equipment intended for global mapping of the composition of main rock-forming elements in lunar soil probed from a low-altitude lunar orbiter is technically feasible. Possible influence of various physical factors present in space near the Moon on the remote elemental analysis is considered, including magnetic and electric fields and the natural background of corpuscular and X-ray radiation at the satellite orbit.