One of the main tasks of surgical treatment of patients with frontal sinus neoplasms with intracranial spread is to seal the subdural space, which is achieved by hermetically connected dura mater. The purpose of this study was to investigate the structure of the tissues of the dura mater and dura mater-fascia junction using bipolar electric welding. The obtained data shows, that electric welding provided a stable advantage in the tensile strength and tightness of the electric welded connection, compared to the connection using suture material. The value of the tensile strength for the connection of the DM with the DM was established - 32.795±0.1 (increase in strength compared to the suture connection by 1.35 times) mm Hg, for the connection of the DM with the aponeurosis of the skull 30, 71±0.37 (1.26 times increase in strength compared to the suture connection), for the connection of DM with the fascia lata was 29.67±0.33 mmHg. (increase in strength compared to a seam connection by 1.22 times). Also the methods of light microscopy and infrared spectroscopy were used. When evaluating the results, no β-structured aggregates were observed in the tissue samples under study. There was minimal traumatic damage to the adjacent dura mater tissue and minimal thermal damage from vaporisation. Pacchioni granulations, venous pial, and cortical vessels of the dura mater were preserved. The study observed complete identity of the wave values of amide A, B, amide I, II spectra; preservation of amide A, B peaks. Preservation and curvature of the N-H arm and O=C-N band were changed within acceptable limits. The findings indicate the absence of β-structured protein aggregates in the junction area, which excludes the possibility of fibrous structures and, as a result, does not contribute to the formation of a meningeal scar. The structure of the collagen protein in the junction area is normal, altered but intact, with preservation of its functions. This indicates the feasibility of using the method of high-frequency bipolar electric welding for surgical closure of defects of the dura mater, as an alternative to closure with suture material