In this final paper, The New Austrian Tunneling Method (NATM) will be described. This method has conquered the world and became recognizable as a general concept of tunnel construction. At the very beginning of the paper, the focus will be on tunnels in general, their design and different performance technology. Before moving on to the main subject, traditional tunneling methods that preceded the appearance of NATM will be mentioned briefly. The main part of the paper is about clarifying the origin of the name of the method, the basic principles and the method excavation and the positive and negative aspects of its application. In the end is also described a tunnel built according to NATM principles. It is the „Debeli Brijeg“ tunnel, the most complex object of the project „Road connection with southern Dalmatia“. This practical example at its best way will explain the application of NATM, everything that precedes that application, in terms of geotechnical observations and measurements and finally substructure techniques and their main characteristics.