This paper presents a detailed documentation of LIMES-EU – the Long-term Investment Model for the Electricity Sector of EUrope. LIMES-EU is a linear optimization model that simultaneously optimizes investment and dispatch decisions for generation, storage and transmission technologies. Its integrated approach together with an intertemporal optimization from 2010 to 2050 allows for analyzing comprehensive scenarios on the cost-efficient future development of the European power system. Despite the model’s long-term focus until 2050, LIMES-EU effectively accounts for the short-term variability of electricity demand and the renewable energy sources wind and solar. In order to provide transparency, this paper gives a detailed overview of the model’s underlying assumptions, its input data and a full list of the model equations.