A system for delivering volatile substances (1) comprising a housing (2) inside which a volatile substance is housed a ventilation surface (3) placed in said housing (2) provided with ventilation windows, and a regulating element (4) that can be placed in at least two different positions: a first position of maximum air circulation, and a second position of minimum air circulation and it is characterised in that in said first position, the regulating element (4) opens an additional ventilation opening (A), and in said second position, the regulating element (4) closes said of additional ventilation opening (A). It permits to regulate easily the circulation of air for increasing or decreasing the fragrance, for example, by simply rotating said regulating element.
