The methodology of International Public Law is a component of the science of this same discipline as well as a knowledge area in statu nascendi. It is the teaching handbook on methods for understanding the discipline of International Public Law. The methodology of International Public Law above all is made up of knowledge drawn from the disciplines of the methodology of philosophy and sociology in International Public Law. As a legal order, their most important methods are regulation, genetic process, functionality, analysis, systematisation, structure, comparison, empirical methods, stability, change and prediction. International Public Law does not require the International Relations Theories developed in the United States. This work has been written in the context of basic research conducted, with the view to contribute to the continual development of the science of International Public Law.