The LBNO-DEMO (WA105 experiment) is a demonstrator of a dual-phase liquid argon time- projection chamber concept. This prototype will have a 6 6 6 m 3 (approximately 300 t) active volume and will allow to test industrial solutions developed for a construction of a large under- ground liquid argon detector for neutrino and antiparticle physics. The WA105 detector will be exposed to a well-defined beam of charged particles of different types and momenta to study and calibrate its performance. In these proceedings an overview of the WA105 detector design and its key features will be given. Implementation of the dual-phase detector in the context of the next-generation long baseline neutrino oscillation program will also be briefly discussed