The article 606.1 of the Spanish Criminal Code penalizes the violation of the personal immunity of a Head of State from another country or a person internationally protected by a Treaty. This paper is aimed to analyze the limitations of the concept of immunity in the Spanish legislation and jurisprudence, and to bring a lege ferenda solution, constitutionally acceptable from the Right of the due process of law and the equality principle. Keywords: Immunity. Inviolability. Head of State. Diplomatic and Consular Staff. Incomplete criminal statute. International Criminal Law. International protected persons. Due process. Principle of Equality. Reciprocity. Law of nations. Peaceful coexistence among Nations.