ISO 15632:2021 defines the most important quantities that characterize an energy-dispersive X-ray spectrometer consisting of a semiconductor detector, a pre-amplifier and a signal-processing unit as the essential parts. This document is only applicable to spectrometers with semiconductor detectors operating on the principle of solid-state ionization. This document specifies minimum requirements and how relevant instrumental performance parameters are to be checked for such spectrometers attached to a scanning electron microscope (SEM) or an electron probe microanalyser (EPMA). The procedure used for the actual analysis is outlined in ISO 22309 and ASTM E1508 and is outside the scope of this document.