Invitation and Scope Principals of New Austrian Tunnelling Method (NATM) is generally being applied in the design and construction of the tunnels by different sectors in Turkey. The NATM design criteria used in the Specifications of the General Directorate of Highways is based on Austrian Specifications. Austrian experts will conduct a seminar between 31th March and 1st April, on the modifications in NATM design and construction specifications, on practices developed according to the new specifications and experiences. The participation of engineers working for project, consultancy, construction companies and public bodies in tunnelling sector, academicians and suppliers of tunnelling industrial materials, machinery and equipment to the seminar is expected.