[en] A few years ago, a new form of pure carbon, the fullerenes, has been discovered, which shows many fascinating properties. Within this work the spatial and electronic structure of some selected fullerene compounds have been investigated by electron-energy-loss spectroscopy in transmission. Phase pure samples of alkali intercalated fullerides A_xC₆₀ (A=Na, K, Cs) have been prepared using vacuum distillation. Measruements of K₃C₆₀ show a dispersion of the charge carrier plasmon close to zero. This can be explained by calculations, which take into account both band structure and local-field (inhomogeneity) effects. The importance of the molecular structure can also be seen from the A₄C₆₀ compounds, where the non-metallic properties are explained by a splitting of the t_1u and t_1g derived bands that is caused by electron-correlation and Jahn-Teller effects. First measurements of the electronic structure of Na_xC₆₀ (x>6) are presented and reveal a complete transfer from the sodium atoms but an incomplete transfer onto the C₆₀ molecules. This behaviour can be explained by taking into account additional electronic states that are situated between the sodium atoms in the octahedral sites and are predicted by calculations using local density approximation. The crystal structure of the higher fullerenes C₇₆ and C₈₄ is found to be face-centered cubic