a first cartridge configured to accommodate a first material therein and comprising a delivery hole through which an aerosol generated from the first material is delivered;

a second cartridge comprising a plurality of chambers for accommodating a second material including a granule in a solid state such that the aerosol delivered from the first cartridge passes through the second material and is discharged to an outside of the aerosol generating device, a position of the second cartridge with respect to the first cartridge being changeable so that at least one of the plurality of chambers corresponds to the delivery hole;

an upper plate covering upper ends of the plurality of chambers and including an upper through hole through which the aerosol, which passed through the second material, is discharged out of the plurality of chambers,

a remaining amount sensor configured to detect a remaining amount of the first material accommodated in the first cartridge so as to generate a sensing signal; and

a controller configured to determine, based on the sensing signal, a consumption amount at which the first material is consumed with respect to a usage chamber that currently passes the aerosol among the plurality of chambers, compare the consumption amount of the first material with a pre-set reference consumption amount of the first material with respect to the usage chamber, and determine a position changing time at which changing of a position of the second cartridge with respect to the first cartridge is required,

wherein each of the plurality of chambers comprises a lower through hole which is positioned under the chambers, and

wherein the aerosol delivered from the delivery hole passes through the lower through hole and is delivered toward the second material.