The problem of metrological support of high-voltage pulse generators with subnanosecond rise time, as well as pulse voltage dividers used in power engineering, aviation and rocket-space industries, has been solved. As a result of the modernization of the State primary special standard of transient electric and magnetic field strengths units with a pulse rise time in the range of 0.1–10.0 ns GET 148-2013, a mode of realization a unit of high transient electric voltage with a minimum pulse rise time of 100 ps was implemented. Uncertainties of high transient electric voltage unit realization obtained by numerical simulations using the Monte Carlo method, as well as in accordance with the Guide to the Expression of Uncertainty of Measurement (GUM), are estimated. Also, the error of a unit realization was estimated in accordance with GOST 8.381-2009 “GSI. Standards. Methods to Express Accuracy”.