The task of this thesis was to analyze in detail the effective length of the simplest version of the type A grounding system in accordance with the HRN EN 62305 standard set during a lightning strike to its central point. In the thesis, the grounding system considered consists of two opposing elementary grounding conductors and is buried parallel to the ground surface in homogeneous soil. The second chapter describes the main features of the type A grounding system in accordance with the HRN EN 62305 standard set. The version of this grounding system used in this paper, which consists of two opposing horizontal elementary grounding conductors, is also described. The third chapter defines the concepts of impulse impedance of the considered grounding system and effective length of the grounding system. The fourth chapter describes the EMGround program that was used to obtain the most accurate values of the effective length of the considered type A grounding system. In addition, the iterative procedure for finding the effective length within this program is briefly described. In the fifth chapter, the influence of the burial depth of the considered grounding system on the effective length for different values of the impulse current wavefront duration and for different values of the homogeneous soil resistivity is analyzed in detail. For eight values of the homogeneous soil resistivity, ten values of the wavefront duration and five values of the burial depth, 400 simulations were performed in the EMGround program in which the effective length was iteratively sought for each case. The analysis of the obtained effective lengths revealed a pattern of similar reduction in the effective length due to an increase in the burial depth, regardless of the values of the wavefront duration and the homogeneous soil resistivity. This influence is described by the factor of reduction in the effective length of the earth electrode due to the burial depth in relation to the effective length of the earth electrode at a depth of 0.1 m. An approximation formula for the mentioned factor was developed in MATLAB’s Curve Fitting Toolbox and its accuracy was confirmed in the same chapter. In the sixth chapter, ten values of the resistivity of homogeneous soil and ten values of the wavefront duration were selected and the effective length of the considered grounding system at a burial depth of 0.1 m was calculated using the EMGround program. It was shown in the previous chapter that the obtained effective lengths can be converted to other burial depths using the factors developed in that chapter. By analyzing these one hundred obtained effective lengths, four approximation formulas were developed that can quickly and accurately calculate the effective lengths of the considered grounding system for any combination of parameters within the prescribed intervals. In the seventh chapter, two short numerical examples are given in which practical examples of calculating the effective length of a type A grounding system for different parameter values are presented.