A porous silicon wafer with embedded ferromagnetic nanostructures is a hybrid system possessing the electronic properties of silicon together with the magnetic properties of the incorporated ferromagnetic material. One goal of the investigation is to elucidate the size, crystallographic orientation and distribution of the magnetic particles in the porous silicon structure in dependence on the electrochemical deposition parameters. The results are correlated with magnetic measurements. But also knowledge of the bonding of the magnetic particles to the pore walls is extremely important for a sound interpretation of the results of the magnetic measurements. For this purpose also preparation methods for thin sections of porous materials without any damage of the structure have to be developed. For the investigation the entire spectrum of electron microscopic methods is used: SEM / EDXS / EBSD, TEM / EDXS / EELS and also tomography by TEM. But also vibrational spectroscopy like micro-Raman and micro-Infrared will be involved.