The issue of work motivation may seem to have become exhausted - the decreasing number of works indicates that. In fact, there are problems understanding the nature of the phenomenon and, thus, managing it. In the 20th century, the principle of self-organization in open systems that has its origins in natural sciences was employed in social sciences, introducing human-centered management. This requires redefinition of the basic principles of employee motivation. This book is an attempt at taking a step closer to a better understanding of work motivation addressing both principal theoretical approaches and empirical data received from a survey of civil servants' work motivation and job satisfaction. The author offers a model of work motivation and satisfaction focusing on the employee's needs. The book investigates possibilities of work motivation management in the public sector, although the principles can easily be employed also in the private sector.