This book provides an accessible introduction to quantum electrodynamics. Based on lectures on quantum electrodynamics given by the highly original and distinguished physicist V. N. Gribov, the aim of the book is to present the theory of quantum electrodynamics in the shortest and clearest way for applied use. A distinctive feature of Gribov's approach is the systematic use of the Green function method which allows a straightforward generalization to the cases of strong and weak interactions. The book starts with an introduction that uses the basics of quantum mechanics to gently introduce the reader into the world of propagation functions and particle interactions. The following chapter then focusses on spin 1/2 particles. The text goes on to discuss symmetries, the CPT theorem, causality, and unitarity followed by a detailed presentation of renormalisation theory. A final chapter looks at difficulties with the theory and possible routes to their resolution.