This Practice Note looks at the Capacity Market (CM) introduced under the electricity market reform (EMR) programme. It provides an introduction to the purpose and legal basis of the Capacity Market, explains what types of electrical capacity Capacity Market support is available to, how Capacity Market support is won, and the form that Capacity Market support takes. It also provides an overview of the key parties involved in the Capacity Market and explains how the pre-qualification and auction processes work in summary. The Practice Note includes a brief analysis of the annulment and subsequent re-confirmation of EU state aid clearance for the Capacity Market mechanism, following the General Court’s 15 November 2018 judgment in respect of Case T-793/14 Tempus Energy Ltd and Tempus Energy Technology Ltd v Commission.