This thesis studies the characteristics and possibilities of using the computer program NEPLAN in engineering practice and for teaching purposes, with a special emphasis on the short-circuit analysis module. NEPLAN is an extremely powerful software tool used to perform analyses and calculations of various network states. The program allows parameterization of elements down to the smallest detail, and the calculations are performed at high speed. Detailed modeling of system elements ensures this program high accuracy even with many elements in the system. The NEPLAN V553 version of the program was used in this paper. After the introductory part, the basic characteristics of short circuits according to the HRN EN 60909 standard are described. An overview of the basic formulas required for calculating the equivalent impedances of electrical elements required for calculating short-circuit currents is given. This chapter of the thesis also describes the basic components of short-circuit currents. A description of the symmetrical components for the four basic types of short circuits and short circuits through fault impedance is also given. The third chapter describes the general part of the NEPLAN program, the appearance of the graphical user interface, and the method of data management in the program. The program modules that are most often used in the program are also described, with special emphasis on the short circuit analysis module. The fourth chapter follows, in which the method of parametrizing the elements and performing the simulation necessary for the calculation of short-circuit currents is described. In the fifth chapter, an example of three-phase and single-phase short-circuit analysis on selected buses of a given network is given in the NEPLAN program. In order to verify the accuracy of the results in the NEPLAN program, the calculation of the short-circuit currents on the same network was also performed in the PowerCAD program.