Record production in use of TBM-EPB machine on second underground line in Warsaw Currently, the project of the second line of Warsaw underground constitutes the largest infrastructural project in Poland and one of the most important in the European perspective. In fact, it is considered one of the largest and most interesting challenges from the point of view of the time of its implementation, intended works, position, as well as geologic and geotechnical conditions. The consortium which is implementing the project consists of an Italian-Turkish-Polish group, which developed the final project plan as well as the executive and construction plans of more than 6 km of two-channel tunnels with 5,40 m internal diameter, 7 stations, 6 ventilation shafts, and all must be completed within 48 months. Below we present the criterion for the selection of the most effective method of tunnel boring: the Tunnel Boring Machine (EPB type), taking into account various factors, such as, for instance, geologic and geotechnical conditions, available space, previous experience, and so on. In addition, this publication will present characteristic features of the machine, primarily taking into account a number of distinctive aspects which are sometimes overlooked or even forgotten, such as daily consumption of energy, even issues related with the environment, too. Moreover, it will be considered how this detailed and accurate study, even though in the greatest details going beyond the framework of general planning, despite of being flexible from the functional point of view in comparison with the tunnel boring development program, has surely reduced the delays in excavations which were not affected neither by events nor contingencies caused by the Contractor itself. Finally, attention will be drawn to the purchase of 4 shields, necessary to speed up the work, with enhanced, excellent performance and record productions in very difficult field conditions.