Provided is an aerosol generating device including at least one component accommodating space having an opening on an outer surface of the aerosol generating device and allowing a removable component to be accommodated therein through the opening; a controller configured to periodically generate a test signal; a detection signal generator configured to generate a flooding detection signal based on the test signal when a liquid is introduced through the opening; and a detection signal transmitter configured to receive a generated flooding detection signal and transmit the received flooding detection signal to the controller, wherein the controller determines whether the aerosol generating device is flooded based on the flooding detection signal.