This book presents a systematic study of the most important topics of vector optimization such as the existence of efficient points, optimality conditions, scalarization, duality, and the structure of optimal solutions sets. New methods to which particular attention is paid are the theory of nonconvex analysis or analysis over cones, the theory of contingent derivatives of set-valued maps, and the nonstandard approach to duality. By reading this book, graduate students can easily comprehend basic concepts and the most important methods of vector optimization. The researchers who are familiar with this theory will find in the book several new approaches to the subject together with the latest results on it.