This book comprises a study of ethics and public integrity issues in the administrative services of the European Commission. The author traces the reforms implemented in this area since the early 2000s, and asks whether and how they have shaped Commission officials’ thinking about appropriate behaviour in public office. Based on in-depth interviews and the use of vignettes, the book reveals that the influence of ethics regulations is subtle and full of contradictions: while a heightened awareness and discussion of ethical issues exists in the Commission nowadays, the topic is nonetheless often considered as a matter of "common sense". This book breaks new ground as the first analysis of ethics at the level of individual EU officials. It advances a new angle to the study of the Commission as an administrative actor, and sheds light on an important but under-researched component of its efforts to address criticism concerning democratic legitimacy. In the field of administrative ethics, the book tackles research gaps regarding the practice and impact of ethics policies within public organizations.