The self-consistent model of processes in argon plasma sheath is presented in our study. The scattering processes are simulated stochastically by means of Monte Carlo method. The motion of charged particles in a non-uniform electric field is solved by the Verlet algorithm. The developed model includes only two important processes, i.e. elastic scattering of electrons on argon neutrals and the resonance charge transfer for positive argon ions. Our results obtained by the computer modelling for two various pressures in DC discharge in an argon gas are compared.