The process of building and modernizing the high voltage substations generate the problems concerning the determination of the optimal technological solutions, which should be friendly to the environment, meet the criteria of sustainable development and be cost effective. Since many institutions are involved in the decision making process to reach an optimal solution for the planned substation, consensus is sometimes not possible without the commitment of the instruments which support this decision. Hence, in this paper the authors proposed a new approach based on the Analytic Hierarchy Process (AHP) method in relation to supporting the decision of choice of high voltage substation technology between two commonly applied solutions: Air Insulated Substation (AIS) and Gas Insulated Substation (GIS). On the basis of applied regulations as well as expert opinions a survey was prepared and then analyzed in terms of the elaborated criteria. The results show that the AHP method is well suited to the issue under consideration, indicating clearly that GIS technology is strongly preferred. Hence, this opens the discussion for the use of the AHP method in a wider form in the decision support process in the specific field, which high-voltage engineering is.