This Chapter presents highlights about spectrum monitoring. As noted earlier, spectrum monitoring is an essential tool for spectrum management because of its ability to: monitor and take measurements of signals; detect and identify unauthorized stations; determine station locations for further enforcement actions; and identify the source of harmful interference. Administrations interested in establishing spectrum monitoring facilities are encouraged to read the ITU-R Handbook on Spectrum Monitoring, ITU-R Recommendations and ITU-R Reports identified in the relevant ITU--R References provided before the annexes of this report, for additional details. Furthermore, the reader is advised that the ITU Academy provides training in spectrum monitoring.