This paper tries to focus Sophocle's Electra from a point of view interested on early legal aspects, that were sketched around the big theme of revenge. All this belongs to the social and cultural frame in which the legislation of the Greek people originated and developed. In order to achieve this study, the authoress makes a review of the mention in the prologue of enthronizing rites that, added to the commandement of the Apolo's oracle, would permit Orestes to assume the function of Delphic god when he proclaims himself as kaqartÉj.