The continuous electrical resistivity measurement, while an interesting parameter is being changed, can be a useful tool for in-situ thin film analysis as most changes in films are accompanied by changes in the electrical resistivity. In-situ measurements in a tube furnace at atmospheric pressure during different heat treatments are presented for oxidation tracing in Cr films and the TiN/CrN multilayer and for detection of interactions in Ni/Si, Ti/Si and Ni/Al multilayers. Results of electrical resistivity measurements can be correlated well with weight gain measurements, X-ray diffraction, Rutherford backscattering spectroscopy and Auger electron spectroscopy depth profiling. It is therefore shown that the measurement of the resistivity with its time and temperature derivatives can represent a useful basis for the application of other analytical methods.