The present invention relates to the cosmetic use as active mattifying of at least a hyaluronic acid, or one of its salts. It also relates to a cosmetic process for giving it a matt effect and / or reduce the brightness of a keratinous material, in particular of the skin, comprising a step for topical application on keratinous matter of a composition comprising a hyaluronic acid, as active mattifying, said composition being rinsed after application to the keratinous substance. There are also claimed a mask (not - occlusive comprising a composition comprising at least a hyaluronic acid or one of its salts, as well as a kit in order to render the skin, comprising at least a receptacle containing a composition comprising at least a hyaluronic acid or one of its salts, one or more masks not - occlusive, preferably non - woven, for single use only, and a mode of use, indicating the protocol of the use of this composition, specifying at least the steps of the process according to the invention.
