This book presents the concepts‎,‎ methods and applications of kinetic theory to rarefied gas dynamics‎.‎ After introducing the basic tools‎,‎ problems in plane geometry are treated using approximation techniques ‎(‎perturbation and numerical methods‎)‎‎.‎ These same techniques are later used to deal with two‎- and three‎-dimensional problems‎.‎ The models include not only monatomic but also polyatomic gases‎,‎ mixtures‎,‎ chemical reactions‎.‎ A special chapter is devoted to evaporation and condensation phenomena‎.‎ Each section is accompanied by problems which are mainly intended to demonstrate the use of the material in the text and to outline additional subjects‎,‎ results and equations‎.‎ This will help ensure that the book can be used for a range of graduate courses in aerospace engineering or applied mathematics‎.‎