Article 50TEU acknowledges the right of Member States to withdraw from the EU, and contains a specific procedure. It also constitutes the legal basis of an exceptional EU competence whose purpose is to ensure that a Member’s departure is “orderly”. This qualification entails the conclusion of an agreement between the parties on the terms of the withdrawal, but also presupposes that the withdrawal does not undermine the integrity of the EU legal order, while contributing to the fulfilment of the Union’s integration objective. The unprecedented exercise of that competence has enriched the law of European integration: core components of the constitutional identity of the EU have been (re)affirmed, the role of its institutions bolstered, and Union membership law further articulated. Paradoxically, withdrawal may therefore be envisaged as an integration-friendly process.