An aerosol generating system comprising: a main body; a cartridge detachably coupled to the main body, and comprising an air inlet hole through which external air is introduced, and wherein the cartridge is configured to store a liquid material and generate aerosol by heating the liquid material; a cigarette detachably coupled to the main body, and comprising a solid material, and wherein the cigarette is disposed on a path along which the aerosol generated in the cartridge flows such that the aerosol passes through the solid material and is discharged to outside; and a cover detachably coupled to the main body to cover the cartridge coupled to the main body and comprising: a cigarette hole through which the cigarette is coupled to the main body; and a ventilation hole formed at a position adjacent to the air inlet hole of the cartridge and configured to discharge the aerosol remaining in the cartridge to the outside or introduce the external air; wherein the cartridge further includes a liquid heater for heating the liquid material, a chamber surrounding the liquid heater to define a space in which the aerosol is generated, an outlet connecting the chamber toward the cigarette to discharge the aerosol toward the cigarette, and an air passage connecting the chamber and the air inlet hole to each other; and wherein the air passage extends in the direction in which the cigarette extends, and the cigarette and the air passage are arranged substantially in parallel with respect to the direction in which the cigarette extends. a main body; a cartridge detachably coupled to the main body, and comprising an air inlet hole through which external air is introduced, and wherein the cartridge is configured to store a liquid material and generate aerosol by heating the liquid material; a cigarette detachably coupled to the main body, and comprising a solid material, and wherein the cigarette is disposed on a path along which the aerosol generated in the cartridge flows such that the aerosol passes through the solid material and is discharged to outside; and a cover detachably coupled to the main body to cover the cartridge coupled to the main body and comprising: a cigarette hole through which the cigarette is coupled to the main body; and a ventilation hole formed at a position adjacent to the air inlet hole of the cartridge and configured to discharge the aerosol remaining in the cartridge to the outside or introduce the external air; a cigarette hole through which the cigarette is coupled to the main body; and a ventilation hole formed at a position adjacent to the air inlet hole of the cartridge and configured to discharge the aerosol remaining in the cartridge to the outside or introduce the external air; wherein the cartridge further includes a liquid heater for heating the liquid material, a chamber surrounding the liquid heater to define a space in which the aerosol is generated, an outlet connecting the chamber toward the cigarette to discharge the aerosol toward the cigarette, and an air passage connecting the chamber and the air inlet hole to each other; and wherein the air passage extends in the direction in which the cigarette extends, and the cigarette and the air passage are arranged substantially in parallel with respect to the direction in which the cigarette extends.