A device (1) for delivering a substance in the form of aerosol, used in combination with a syringe (101) equipped with plunger (103) and without needle, which delivery device (1) comprises； - a connection sleeve (4) for connecting the device (1) with the syringe (102)； - a nozzle (53) for delivering the substance in the form of an aerosol, preferably with troncoconical walls and obtained on an elongated outer body (2) of the device (1)； and - a fluid-dynamic path (5) comprised between the connection sleeve (4) and the dispensing nozzle (53), which path (5) comprises an annular expansion chamber (50) and an elongated acceleration chamber (52), so that, in use, a manual actuation of the plunger (103) produces the input of the substance in liquid form in said fluid-dynamic path (5) through the connection sleeve (4) and the outlet of the substance in the form of an aerosol through the dispensing nozzle (53).
