The paper analyses vacuum gauge accuracy problem, which leads to the pressure deviation in vacuum nano-coating deposition process. Pressure deviation leaves significant impact on vacuum coating properties and quality. Therefore, new vacuum gauge verification methodology has been developed and the results are presented in this paper. Methodology consists of combination of several verification methods, including a method of constant pumping speed, method of comparison to the reference gauge, Student's t-distribution and other methods and approaches. In the following research, several experiments with ionization and diaphragm vacuum gauges were performed to obtain data on their accuracy and to validate thereof. Proposed methodology focuses on vacuum gauge multifunctional verification under manufacturing conditions, resulting in correction coefficient implementation for vacuum gauges. Developed methodology determines a necessity and a period of calibration to be needed for each vacuum gauge.