Multicomponent thin alloy films based on Ni-Cr with additions of aluminium have been used in the G.D.R. for the production of discrete thin film resistors for more than 10 years. Additions of aluminium stabilize the layer and reduce the temperature coefficient of resistance (TCR) to values of about zero. Three regions have been found up to now in the system Ni-Cr-Al which result in highly stable resistive films with a very low TCR. The properties of these films are determined by the content and the distribution of the phases which are present in the amorphous film. The following phases have been found in structural investigations of vacuum-annealed films: α phase (chromium), β phase (NiAl), γ phase (Ni 3Cr), γ′ phase (Ni 3Al) and γ-γ′ phase (Ni 3(Cr, Al)). Of the three regions, one with less than 3 at.% Al, one with 28–32 at.% Al and one with 45–60 at.% Al, the first two regions have been used for the production of thin film resistors up to now. Films of the third region, which has only been found during the last few years, can be obtained by sputtering.