The book is the first attempt to present the main principles of thermodynamics of irreversible processes in the form of thematically selected problems with solutions and instructions. It includes more than one hundred problems on general and special issues of linear and nonlinear thermodynamics of irreversible processes, on issues covering a wide range of phenomena of energy transfer, mass and momentum in thermodynamic systems complicated by phase transformations, viscous and plastic motion of the medium, dissipation of energy in gases and plasma, relaxation phenomena and chemical reactions in a magnetic field.