Multilayer structures for electrochromic devices have been produced using vacuum evaporation and electrochemical deposition, and have been optically and electrically characterized by real time measurements. The deposited structures consist of a five layer stack comprising a transparent electrode (indium tin oxide) on glass substrates, an electrochromic active layer (W03), an electrolyte, a complementary electrochromic film (prussian blue) acting as a reservoir for the active layer, and a second transparent or reflecting electrode. In order to determine the process dynamics, real time transmittance and reflectance spectral analysis on the visible range have been performed using a multiple analysis system (OMA), during colorswitching of the device, in coordination with electrical characterizations of the switching process by current and charge transfer measurements. These measurements were performed as a function of time and of the driving voltage, and provide a means of determining the structural parameters of the device through the switching time and the current transient.