Aerosol generation method and apparatus

An aerosol generating device comprising:

• a casing configured to accommodate a cigarette in an empty space formed at a terminal end of the casing;
• a heater located inside the empty space and configured to heat the interior of an accommodated cigarette through a needle-type structure;
• a controller;
• and
• a battery configured to supply power needed for operations of the heater and the controller,
• wherein the heater comprises:
• a heating unit comprising a base portion having a cylindrical shape and a tip portion formed at one terminal end of the base portion;
• a first sheet comprising an electro-conductive track formed on one surface and surrounding at least a portion of an outer circumferential surface of the base portion;
• and
• a coating layer covering the heating unit and the first sheet,
• the first sheet constitutes a stepped surface formed by a stacked structure surrounding at least a portion of the outer circumferential surface of the base portion, and
• the coating layer planarizes the stepped surface formed by the stacked structure.