The European air traffic management system is characterized by its dynamic and diverse nature. To effectively address future challenges, it is crucial to enhance efficiency and resilience within the system. As an integral part of the air traffic system, air navigation services operate as natural monopolies and are subject to regulatory measures. While operational and academic studies regularly address performance benchmarking, no comparative analysis is currently evaluates the different approaches. This paper introduces a fundamental analysis for evaluating the technical efficiency of air traffic control at the air navigation service provider (ANSP) level. Our research encompasses the development of an economic model, the application of various analytical methods, and the careful selection of units for evaluation. Our findings demonstrate that the standard Data Envelopment Analysis (DEA) method is highly effective. Additionally, we emphasize that not all ANSPs shall be included in the analysis, and we caution against incorporating monetary inputs and outputs in the model.