The innovation systems approach examines the institutional architecture of innovation processes from a Schumpeterian perspective that is most commonly referred to in the literature of evolutionary economics. In recent decades, it has been commonly used in innovation studies in general, while being utilized in diverse policy texts of governments and international organizations. A national innovation system comprises those networks of private- and public-sector institutions in a national context whose interactions contribute to the generation and diffusion of new technologies and, thus, significantly shape the international competitiveness of a country. The analytical focus is particularly on interactions between companies, research institutions, state actors, and financial institutions. The state is singled out as an entrepreneurial actor, which provides impulses for research and innovation. Recent advances in this approach have extended research efforts to address regional and local as well transnational and supranational innovation systems, while putting more emphasis on the matter of institutional change.