The accuracy of shower parameter reconstruction expected for the KASCADE EAS array has been studied by a detailed Monte Carlo simulation. Air showers induced by photons, protons and iron with primary energies in the range of 3×10 14 to 4×10 15 eV have been propagated through the array to investigate its response behaviour both for the e/γ- and the muon-detector components. The methods of raw data analysis are described and it is shown that all relevant shower parameters of the e.m. component can be reconstructed with considerably better accuracy compared to the intrinsic shower fluctuations. Besides this, the measurement of the muon content of the showers is another essential aspect of the KASCADE experiment. The simulations predict, that the number of muons hitting the array can be determined within an accuracy of about 6%. The total size of the muon component can be reconstructed with better than 20% accuracy.