The Author analysis the role of international courts in the understanding and implementation legal institutions situated on the border between public international law and domestic law, on the example of the jurisdictional immunity of the state. The level of contact of those institutions under discussion relates to state’s using the immunity and human rights protection with special regard to the access to the court. The functions of international courts in discussed scope are particularly important in the opposite to public international law powerlessness according to the codification of its fundamental institutions. The lack of the treaty regulations and low specificity of custom norms relocate the liability of analyzing the substance, the scope of application, the admissibility of the limitation of immunity on international courts, whom statements can be a pattern for domestic courts. Unfortunately the judgments of international courts as well as domestic ones are not consistent – example of what are the differences in the approach to the immunity between European Tribunal of Human Rights and International Court of Justice. The lack of consistent vision of jurisdictional immunity is typical for international and domestic courts and in general is nothing special. However significant differences in the statements of main international courts deepen the uncertainty according to immunity’s scope, substance, possibilities of limitation (or lack of possibilities of limitation), that is especially deep regarding to simultaneous slowdown of codification activity.