An aerosol generating device includes a heating element configured to heat an aerosol generating material, a battery configured to supply power to the heating element and receive power from an external device, an output unit, and a processor configured to control the output unit to output a notification indicating whether the aerosol generating device is usable, within a predetermined time period after power supply from the battery to the heating element is discontinued, or within the predetermined time period after the battery is charged to a predetermined level.