This thesis deals with the emergence of the airport as a new strategic actor in the air transport system which has undergone profound changes since its liberalisation and within which the airport turned out to be a major player. Considering the airport as an actor in the air transport system, even if it is affected by its environment in a large sense, this work proposes a contribution to current discussion about airport economics. This contribution refers to two levels : an analysis of the European airport business within which the airport emerges as a full player and an analysis of the link between airport strategy and the spatial and territorial context into which the airport is embedded. Based on the differentiation of airport strategies...