This book is a modern pedagogic introduction to the ideas and techniques of quantum field theory.After a brief overview of particle physics and a survey of relativistic wave equations and Lagrangian methods,the quantum theory of scalar and spinor fields, and then of gauge fields,is developed The emphasis throughout is on functional methods,which have played a large part in modern field theory. The book concludes with a brief survey of `topological objects in field theory and,new to this edition,a chapter devoted to supersymmetry.此书为英文版！