Ministries of foreign affairs are prominent institutions at the heart of state diplomacy. Although they have lost their monopoly on the making of national foreign policies, they still are the operators of key practices associated with diplomacy: communication, representation and negotiation. Often studied in a monographic way, ministries of foreign affairs are undergoing an adaptation of their practices that require a global approach. This book fills a gap in the literature by approaching ministries of foreign affairs in a comparative and comprehensive way. The best international specialists in the field provide methodological and theoretical insights into how best to study institutions that remain crucial for the world diplomacy.