The invention relates to a nebulization device (1) for medical mixture, of the type comprising : a containing ampoule (2) for medical mixture, comprising an upper component (2a) and a lower component (2b) connected to each other; at least one emission opening (11) of said nebulized medical mixture from the ampoule (2), and at least one entry window (19) for the intake of air within said ampoule (2); as well as at least one atomizer (14) for the intake of pressurized gas, within the lower component (2b) of the ampoule (2), the atomizer (14) being surmounted by the upper component (2a). Advantageously, at least one, preferably two selection side windows (24) are provided on the upper component (2a), the opening of said selection side windows (24) being shielded by shielding means (16), moved by a command shaft (17).