Treballs Finals del Màster d’Energies Renovables i Sostenibilitat Energètica, Facultat de Física, Universitat de Barcelona, Curs: 2016-2017, Tutors: Miguel Villarubia, Oriol BarberEnergy management is a basic strategy in any current company, especially if it is part of one of the countries of the European Union, and even more after the implementation of the European Decree (Decree 2012/27/EU), transcribed in Spain through RD56/2016, which dictates that the 20/20/20 target for 2020 must be reached. That means that energy consumption is reduced by a 20%, which helps to improve energy efficiency, translated into economic gain. Likewise a 20% of renewable energies in the total energy generation calculated increases, reducing dependence on external fossil energies and the 20% reduction of greenhouse gas emissions as a measure in favor of environmental care and against the effects of climate change. The RD offers two options for the companies to choose. Either implementing an energy management system that helps to reach the target dictated, or being energetically audited by an external company specialized in energy management. This final master's project focuses on the second option. It is based on the energy audit to a commercial area of a German supermarket company operating in Spain, which has hired the services of the company Dekra Ambio SAU, with whom I did my internship and work as a technician later. The paper describes the entire process that must be followed to carry out the audit, from the data collection and inspection of the establishment and its energy consumers, to the analysis and treatment of the data obtained to generate the energy study and finally offer corrective measures to ensure the compliance with RD 56/2016.