In this paper, we propose a method for the experimental determination of an indicatrix of elastic scattering of an electron by an atom based on probe measurements of the distribution function of scattered electrons in the transit mode of a low-voltage beam discharge. We solved the Boltzmann kinetic equation by the method of series expansion according to the number of collisions and experimentally determined the scattered part of the electron distribution function by the method of a planar one-sided probe, which we previously developed for the study of beam discharges. The method was tested in plasma of a low-voltage beam discharge in He. Good agreement was obtained between the experimentally measured indicatrix of elastic scattering of electrons with energy of 30 eV by He atoms and the known data on the differential cross section, including those obtained from beam experiments. It is shown that no a priori data are required for the implementation of the developed method for determining the indicatrix of elastic scattering of an electron beam by atoms.