This research focuses on emerging technologies in the European air traffic management (ATM), specifically investigating technology adoption by the main stakeholders. The European ATM consists of a highly fragmented aviation infrastructure, built and managed by actors with diverse interests. Rapid developments in information and communication technologies affect the European ATM, as also the case with other network industries. Air Navigation Service Providers (ANSPs) and the industry, more generally, started experimenting with digital technologies, such as Virtual Centre (VC), and Flight-Centric Operations (FCO), also known as Sector-less ATM, technologies. These technologies have the possibility to disrupt or at least change the current air navigation services (ANS) provision. However, there is lack of research related to the possible adoption of these technologies in the context of the European ATM in general and the Single European Sky (SES) in particular. This PhD thesis investigates the possible adoption of two emerging technologies using two case studies: flight-centric operations and virtual centre on the European ATM. The following two questions will be answered in this thesis. The first research question is: How and to what extent will emerging technologies - in particular flight-centric operations and virtual centre be taken up and ultimately adopted by the relevant actors of the European ATM? The second research question is: What will the consequences of such adoption be on the process of implementing the Single European Sky? In order to analyze, understand and evaluate the technology adoption, this thesis takes a socio-technical approach using stakeholder theory (ST), combined with actor-network theory (ANT) methodology. Different from the traditional technology adoption research approaches, such as innovation diffusion, an interpretive stance is taken to examine how new technologies come into existence and evolve. The processes of ANT, packed into problematisation, interessement, enrolment and mobilisation are used to explain the adoption of flight-centric operations and virtual centre technologies. Coupled with investigating the factors and barriers affecting the technology adoption, the thesis presents a conceptual framework to examine technology adoption in the European ATM. The data is collected qualitatively through participant observation, interviews and document analysis. The interactions between the key actors are analyzed for further recommendation on the adoption of these new technologies.