Trelaze, 10 km south of the university city of Angers, has been called the slate capital of France, and some slate is still worked in the area. From the 1840s most slate in the region was extracted from shaft mines that gave access to underground chambers, drained by steam engines.
The museum has developed from the work of the Friends of the Slate Industry, an association established in 1979. A sixteenth century house, the Maison de l’Union and a former match factory display collections of tools, machines and working models. One display features the work of women employees in the slate industry. Other displays illustrate the uses of slate, and former miners demonstrate splitting techniques. A network of paths takes visitors through a quarry landscape extending over 3 ha. A 600 mm gauge railway system serving present-day workings ceased operation in 2001.