Principles of Plasma Electrodynamics deals with plasmas and plasmalike media. The text is divided into three parts. The first part treats the linear electrodynamics of homogeneous plasma in equilibrium; the second is dedicated to linear electrodynamics of a spatially inhomogeneous non-equilibrium plasma, i. e., the theory of plasma instability. Finally, the principles of nonlinear plasma electrodynamics are outlined. The textbook contains a large number of exercises with solutions. This textbook is based on the course of lectures that was given by professor A.A.Rukhadze for the students of the department of physical electronics of Lomonosov MSU during the 1966-2006 years.