4Elementary particle physics is a mature subject, with a wide variety of topics. Size considerations require any text to make choices in the subject matter, and such choices are to a large extent a matter of taste. Each topic in this text has been selected for its accessibility to as wide an audience of interested readers as possible, without any compromise in mathematical sophistication. There are of necessity a lot of formulas, but every one is derived, and an effort has been made to explain the various steps and clever tricks, and how to avoid pitfalls. The text is supplemented by exercises at the end of each chapter. The reader is urged to do the exercises that are designed to increase one's skills in the material. The goal of the book is to bring to undergraduates an ability to enjoy this interesting subject.