Translation of the book by the largest modern theorist P. P. Feynman, whose name is well known to readers, is the first of the books in the . series. The lectures underlying this book are imbued with the spirit of scientific and pedagogical innovation. The practical foundations of the theory of fundamental particles are set out on the basis of the minimum amount of information from quantum mechanics, which is set out at the beginning of the book. The translation editor added an afterword highlighting the most significant changes in science in recent years. Tables of elementary particles according to 1976 data. were also added.