This monograph presents a comprehensive geological and geodynamic justification for the construction of underground hydrogen storage facilities in salt-bearing formations of the Izmail district, Odesa region, Ukraine. The research applies an integrated Structural-Thermal-Atmo-Hydro-Geochemical Diagnostics methodology, combining satellite interpretation, morphostructural analysis, field measurements, and laboratory studies. A total of 278 land-based and 149 aquatic observation points were surveyed to assess permeability, geodynamic activity, and stability of the salt formation. As a result, fluid-impermeable and geodynamically passive zones were identified, confirmed as suitable for potential underground hydrogen storage development. The monograph provides scientific justification, mapping materials, methodological guidance, and recommendations for future engineering and feasibility studies on large-scale hydrogen storage in geological salt structures.