Fuel cells convert electrical energy directly into electricity and are thus an alternative to conventional energy conversion techniques. A detailed knowledge of the different processes in the fuel cell is necessary to develop fuel cells with high efficiency. One aspect is the internal reforming of methane in the anode of SOFC fuel cells. The anode structure is investigated by gas adsorption, diffusion and permeation measurements. The reforming reactivity is determined as a function of the anode thickness to characterize the influence of mass transfer limitations. The preparation of the SOFC anode material ends up in a sintered mix of NiO and YSZ. Temperature programmed reduction experiments are carried out in order to define the condition for complete NiO reduction at a low temperature level.