An isothermal and cion-equilibrium mathematical model was provided for the multicomponent adsorption process. In addition, the software was developed for the VSA-based production of oxygen with the use of a CaX zeolite molecular sieve. The mathematical model and computer software were verified on the basis of experimental data. The study employed a test stand comprising two adsorption columns. The adsorption pressure P-A = 150 and 135 kPa and desorption pressure P-D = 20 kPa were adopted in the experiments. The tests produced oxygen with the purity of 90-94% O-2 (vol), at an efficiency of 55-73% and productivity of 570-850 kg O-2 per ton per day. The calculation results showed good consistency with experimental data. The sorption properties of the adsorbent employed were found to be decisive for the performance and the yield of the VSA process while the diffusion phenomena had a considerably lower effect.