Natural mineral waters can be characterised according to their different thermal, mineral and physicochemical properties. France has a wide scale of natural mineral waters of very varied composition and temperature. Thermal waters do not undergo any treatment and are used on the thermal site with a constant temperature, mineralisation and flow. In France there are about 90 spas; each year more than 600,000 patients benefit from the therapeutic properties of thermal waters. © 2020 Elsevier Masson SAS. All rights reserved.