Aerosol generator having a liquid reservoir (10) defining in a sealed state a volume VR configured to hold an initial volume of liquid VL； a membrane (5) having openings, the liquid reservoir (10) being connected to the membrane (5) to feed the liquid to one side of the membrane, the membrane being oscillatable to transport the liquid through the openings whereby the liquid is emitted in the form of an aerosol on the other side of the membrane, wherein the volume VR of the liquid reservoir (10) before the membrane (5) is oscillated is configured to contain more than 5 ml of gas at an initial volume of the liquid VL of at least 5 ml.
