The invention relates to a diffuser of multiple volatile substances (air freshener liquid, odour absorption formulae, bactericide active substances, insecticides, etc.) comprising two or more containers (2, 2′) placed with a symmetrical or approximately symmetrical arrangement about a central body (1) to which they are joined by corresponding supports (3, 3′) that constitute said central body (1). Each container (2, 2′) holding the air freshener liquid or the desired formulation is closed by an active substance diffuser body (4) that also acts as a stopper and prevents dripping. When the device is at rest only one of the containers is diffusing. To change the fragrance, simply turn the device automatically or manually so that the container that was emanating is in the opposite position with respect to the other container, which will then diffuse its active substance, its evaporation being regulated individually or globally.