Although electromagnetic analysis tools can provide good numerical data about the effects of electromagnetic interference, measurements are the method of choice for obtaining quantitative, accurate data on electromagnetic noise problems. Furthermore, since electromagnetic interference measurements often provide the only data accepted by most regulatory agencies, the measurements and their accuracies have recently become a very important issue in order to regulate and harmonize various electromagnetic compatibility emission and immunity standards. The measurement techniques and instrumentations of most use for making accurate electromagnetic interference measurements are presented in this paper.