Konh-Sham equations are central equations of density functional theory, which describes the ground state of a matter on a quantum level using only charge density as a key variable. Solving Kohn-Sham equations numerically is a challenging and important topic, since if the electronic structure of the matter is known, in theory all it's properties can be solved. Finite element method is an efficient numerical method for solving partial differential equations. In modern physics and chemistry it's use is still relatively rare compared to other more traditional engineering fields. The speak will introduce main features of density functional theory and consentrate on the practicalities of implementation of FEM to KS-equations.