A Monte Carlo simulation method that includes charge exchange and elastic scattering is used to calculate the energy and angular distribution of ions striking the cathode in a DC argon glow discharge. For the case that charge exchange is the only collision process, the Monte Carlo results can be checked by the analytical solution of the Boltzmann equation. In that case, both methods yield the same ion impact energy distribution. The results of the simulation show that the most of ions almost vertically incident on the cathode.