The term soft matter includes various aspects of polymers, liquid crystals, colloids, amphiphiles, glasses, granular and biological materials. Of particular interest and importance in the study of soft matter is to clarify, from a unified viewpoint, the formation of the mesoscopic structures and non-equilibrium states under various external stimuli such as flow, electric, magnetic, stress or optical fields. Research on the structure and dynamics of soft matter will provide us with a new way to regulate the mesoscopic structures. We shall call this fascinating area of physics for the 21st century non-equilibrium soft matter physics, aimed at combining non-equilibrium statistical mechanics and soft matter physics. This volume contains a collection of review articles on the current topics of non-equilibrium soft matter physics written by leading experts in the field. The topics dealt within this volume include evaporation, non-equilibrium fluctuations, structural rheology, and active matter. Some of the issues highlighted in this book are the new outcomes of the national research project supported by Grant-in-Aid for Scientific Research on priority area 'soft matter physics' from the Ministry of Education, Culture, Sports, Science and Technology of Japan.