Silicon metal is one of the most important metals produced from silica by carbothermic reduction in the electric arc furnace which works at high temperatures between 1000 to 3000 ^oC. The objective of this work is to simulate the direct carbothermal reduction of SiO₂ for Si metal by using a thermodynamic calculation of Gibb's free energy minimization with MATLAB^® and Aspen HYSYS^®. The comparison of simulation using MATLAB^® with reference [10] revealed close results. By increasing the mole ratio up to 10 increases the Si formation and  increases the ratio more than 10 mole ratio had very bad results,and not economically viable.  Here we did comparison between simulation results using MATLAB^® with real assumption and ASPEN HYSYS^®.