This textbook introduces the fundamentals of industrial economics. The focus of the analysis is on the decisions made by companies under the conditions of oligopolistic competition with homogeneous and differentiated goods. Central to this are the derivation and explanation of optimal business decisions regarding the action parameters of price, production capacity, product design, product quality, as well as product and process innovation. The relationship between the profitability and stability of cartels and mergers on one hand and market structure on the other is also addressed. A separate chapter is dedicated to the competition law framework of oligopolistic competition. The analysis of the decisions to be made is always presented in text, graphically, and analytically - initially as generally as possible, then specified for a particular case.