The Research Laboratory of French Museums is located on the top floor of the Pavilion de Flore, in the Louvre. The scientific methods used in the study of works of art are divided into four groups: examination, measuring, analyzing, and dating. Among the examination methods, the author particularly describes infra-red reflectography and architectural radiography. For the analyzing methods, she specially describes the spectrometry of microfluorescence used in this laboratory since 1973. For the dating methods, besides Carbon14, she describes a special method-- thermoluminescence--used for dating glass, ceramics, seashells, and bronzes containing ceramics. The article is well illustrated.