This study is a research into firm level innovation activities and the role of the engineers in R&D work. The innovation processes is tried to be explained as a mental labour process. In describing how an innovation occurs, two reference points are taken. The first one is the organization structure of the innovation processes. The second is the nature of engineering work in innovation activities. The theoretical context of the book will be based upon innovation literature in economics and the theory of innovation in labour process theory. As to our methodology, a process approach is pursued considering the research objective. With this aim, case studies are done within three companies in Turkey-one big, one middle size and one small-, which are professionally engaged in innovation activities in the automotive sector. A total of seven in-depth interviews are made with R&D engineers of the corporations. These interviews together with the participant observations constitute the empirical data. The analysis of the problematic is based upon these empirical findings. This book is intended for scholars in economics of technology and sociology of work and professionals in R&D sector.