As ecomuseums are criticized in France, among curators as well as university searcher, the author develops a reflection on the relevance of the ecomuseum concept and its application. In the first part, the nine principles of the «evolving definition» are analysed, which clearly shows that this type is still valid for the present. In the second part, five French ecomuseums, old, new, or in construction are described. Each refers to the same founding texts. For each one the description develops a specific aspect of the evolving definition, which summarizes its character. It appears that it is possible for the concept to be expressed in a rather thorough way. In conclusion, the author says he believes ecomuseums can still be a starting point for reflections and actions in museology.