The invention relates to an aerosol delivery device (A) comprising an aerosol generator for generating an aerosol in the aerosol delivery device with a membrane (1) and a vibrator (7) which is configured to vibrate a fluid and to aerosolise the fluid by the membrane (1). The aerosol delivery device (A) further comprises a fluid reservoir (2) for receiving the fluid (3) to be aerosolised, the fluid reservoir (2) being arranged in fluid communication with the membrane (1), a controller (10) which is configured to sequentially operate the vibrator (7) at a plurality of different vibration frequencies, a sensor (13) which is configured to detect at least one electrical parameter of the vibrator (7) for each of the plurality of different vibration frequencies, and a detector (13a) which is configured to detect the presence of fluid (3) in contact with the membrane (1) and/or in the fluid reservoir (2) on the basis of the dependence of the detected values of the at least one electrical parameter on the vibration frequency. Further, the invention relates to a method of operating an aerosol delivery device (A), the aerosol delivery device (A) comprising an aerosol generator for generating an aerosol in the aerosol delivery device with a membrane (1), and a vibrator (7) which is configured to vibrate a fluid and to aerosolise the fluid by the membrane (1). The aerosol delivery device (A) further comprises a fluid reservoir (2) for receiving the fluid (3) to be aerosolised, the fluid reservoir (2) being arranged in fluid communication with the membrane (1). The method comprises the steps of sequentially operating the vibrator (7) at a plurality of different vibration frequencies, detecting at least one electrical parameter of the vibrator (7) for each of the plurality of different vibration frequencies, and detecting the presence of fluid (3) in contact with the membrane (1) and/or in the fluid reservoir (2) on the basis of the dependence of the detected values of the at leas
