[en] After having recalled problems faced by degassing systems, this guide aims at describing how to diagnose a site of biogas recovery from landfills, which improvements can be envisaged, how to choose among possible recovery and valorisation options, and how to integrate new regulations. Thus, it first gives an overview of stakes and challenges related to landfill gas management optimisation from different points of view (environment, safety, regulation, energy production), and then proposes a classification of storage installations depending on gas management modes (levelling down, destruction by combustion, energetic valorisation). It proposes an overview of technical means to be implemented either for all types of sites, or for different specific and typical cases