The device for diffusing volatile substances comprises two containers (1, 2) to hold respective liquids with respective volatile substances. Each container has at least one aperture closed by a cap (12, 22). The device is configured so that it can be located on a supporting surface with the containers (1, 2) vertically confronting, so that one of the containers is selectively in an upper position or in a lower position with respect to the other container. The container which is in the upper position emanates the volatile substance which it contains, and the other one does not emanate the volatile substance which it contains.
