AbstractA precise and practical x‐ray fluorescence technique using the fundamental‐parameter method and the LAMA computer program for the simultaneous determination of composition and thickness of single‐ and multiple‐layer thin films is reviewed. Results from the analysis of Fe–Ni single‐layer and chromium, Fe–Ni, copper triple‐layer thin films are discussed. The analysis showed that x‐ray absorption and enhancement caused by the inter‐element effect in single‐layer and the inter‐layer effect in multiple‐layer films were corrected properly. The accuracy of the analysis is estimated to be ±1% for composi