SF6 is a dielectric gas with high dielectric strength which is used in high voltage applications related to power equipment technology. However, its global warming potential (GWP) index and staying time in the atmosphere are very high. In this study, SF6 and its alternatives (tetrafluoromethane (CF4), methane (CH4) and carbon dioxide (CO2)) are investigated with regard to insulation and molecular properties by calculating the distribution of electrostatic potentials using Gaussian 09 and Gauss View 5.0 molecular software programs. The molecular orbital values (homo and lumo), energy gap, hardness, electronegativity, total energy and molecular volume of each gas are obtained by this analysis. It has been found that there is a relationship between the electronegativity and the dielectric strength.