This book explores the theoretical contribution of Michel Foucault to the fields of criminology, law, justice and penology. It surveys both the ways in which the work of Foucault has been applied in criminology, but also how his work can be used to understand and explain contemporary issues and policies. Moreover, this book seeks to dispel some of the common misconceptions about the relevance of Foucault's work to criminology and law. Mariana Valverde clearly explains the insights that Foucault's rich body of work provides about different practices found in the fields of law, security, justice, and punishment; and how these insights have been used or could be used to understand and explain issues and policies that Foucault himself did not write about, including those that had not yet emerged during his lifetime. Drawing on key texts by Foucault such as Discipline and Punish, and also lectures he gave at the College de France and Louvain Criminology Institute which offer a more nuanced account of the development of criminal justice, Mariana Valverde offers the essential text on Foucault and his contribution and continued relevance to criminology. This book will be important reading for students and scholars of criminology, law, sociolegal studies, security studies, political theory and sociological theory.