An aerosol generating device comprising: a heater configured to generate aerosol by heating an aerosol generating substance; a battery configured to supply power to the heater; and a controller configured to estimate a remaining life of the battery characterized in that the estimation is based on at least two from among a first output voltage of the battery measured at a first time point, a second output voltage of the battery measured at a second time point that is later than the first time point, and a number of usage times of the aerosol generating device between the first time point and the second time point; that the controller is further configured to: calculate a first voltage drop of the battery by subtracting the second output voltage from the first output voltage; and estimate the remaining life of the battery based on the first voltage drop and a first estimated voltage drop corresponding to the number of usage times; that the first estimated voltage drop is determined in advance based on the first output voltage and the number of usage times of the aerosol generating device, and that the first estimated voltage drop comprises a first maximum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its peak performance, and a first minimum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its lowest performance. a heater configured to generate aerosol by heating an aerosol generating substance; a battery configured to supply power to the heater; and a controller configured to estimate a remaining life of the battery characterized in that the estimation is based on at least two from among a first output voltage of the battery measured at a first time point, a second output voltage of the battery measured at a second time point that is later than the first time point, and a number of usage times of the aerosol generating device between the first time point and the second time point; that the controller is further configured to: calculate a first voltage drop of the battery by subtracting the second output voltage from the first output voltage; and estimate the remaining life of the battery based on the first voltage drop and a first estimated voltage drop corresponding to the number of usage times; that the first estimated voltage drop is determined in advance based on the first output voltage and the number of usage times of the aerosol generating device, and that the first estimated voltage drop comprises a first maximum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its peak performance, and a first minimum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its lowest performance. calculate a first voltage drop of the battery by subtracting the second output voltage from the first output voltage; and estimate the remaining life of the battery based on the first voltage drop and a first estimated voltage drop corresponding to the number of usage times; that the first estimated voltage drop is determined in advance based on the first output voltage and the number of usage times of the aerosol generating device, and that the first estimated voltage drop comprises a first maximum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its peak performance, and a first minimum efficiency estimated voltage drop, which is an estimated voltage drop when the battery is at its lowest performance.