Statistical mechanics is a formalism that aims at explaining the physical properties of matter at the macroscopic level in terms of the dynamical behavior of its microscopic constituents. The scope of the formalism is almost unlimited as it is applicable to systems in any state of aggregation, ranging from plasmas and liquids, to polymers, solids and matter in equilibrium with radiation. The aim of this course is to introduce the principles and methods of equilibrium statistical mechanics and apply them to a number of model systems in order to illustrate the use and extent of the theory in a systematic manner.