High-voltage measurement technology has today become a distinct branch of electrical engineering that can be treated independently. While there have been individual books on parts of this measurement technology for years, other parts have only recently been developed and brought to a certain conclusion in the testing areas of electrical factories. The discussion of measurement-related questions in the committees of the Association of German Electrical Engineers has also gained significant scope in recent years. Therefore, a summary of the current state of high-voltage measurement technology meets a practical need. It is important to note that today, measurement methods are being applied in testing areas that were previously limited to a few specialized laboratories, extending beyond the usual measurement framework—covering measuring devices, machines, transformers, and apparatuses.