This Book deals with the assessment of human exposure to electric fields resulting from different high voltage (HV) electrical equipments inside HV substations. This assessment includes the calculations and measurements of HV substation electric fields. These values are compared to the standard limit values. In specific, this study is performed in order to develop and validate a powerful computation tool able to determine and predict the substation zones where the human exposure limits exceeds the admissible values imposed by the legislation. This is in addition to determine the best scenarios to reduce the field values inside the future designed or rehabilitated substations which exceeds the limit values.