An experimental system has been developed to investigate the formation of FeS2 thin films by sulphuration of Fe films. The change of the film electrical resistance during the whole sulphuration process is measured to investigate the kinetics of the transformation from Fe to FeS2. Two experimental parameters can be changed in a controlled way: the temperature of the Fe thin film and that of the sulphur source. This allows to accomplish sulphurations at different sulphur pressures with different molecular compositions of the sulphur atmosphere. Preliminary experimental results presented in this paper prove that the experimental system is a powerful tool to investigate the FeS2 (and other metallic sulphides) formation mechanism. (C) 2004 Elsevier B.V. All rights reserved.