The minimum health and safety requirements regarding the exposure of workers to the risk arising from electric fields produced inside high voltage (HV) substations is still considered as a competitive topic for utility designers, world health organization (WHO) and biomedical field researchers. Hence, the electric fields levels inside HV substations and their induced current inside human body should be pre-evaluated as early stage in the process of substation design. The object of this paper is to present a method for assessment not only the distribution of power-frequency electric field inside HV substations and the charge at the surface of a human body underneath high voltage equipments inside HV substations, but also the induced currents and current densities along the surface of this body. This method of analysis is based on the charge simulation technique (CSM). This study will serve to explain the biological studies of possible long-term exposure effects to electric fields.