An aerosol generating device (1000, 10000) comprising: a first heater configured to heat a liquid composition accommodated in a liquid storage of a vaporizer (1041, 1130); a puff sensor configured to detect a pressure change in the aerosol generating device (1000, 10000); and a controller (1110, 12000) configured to: determine states of a plurality of sections constituting a puff pattern (400, 500, 600, 700, 800, 900) representing a pressure change over time, based on a signal received from the puff sensor, characterized in that the puff pattern (400, 500, 600, 700, 800, 900) includes a pressure maintaining state, a pressure falling state, and a pressure rising state, and control an operation of the first heater, based on the states of the plurality of sections, wherein the plurality of sections include a first section and a second section following the first section, and the controller (1110, 12000) is further configured to start the operation of the first heater based on the first section being determined as the pressure maintaining state and the second section being determined as the pressure falling state; and wherein the plurality of sections include a third section following the second section and a fourth section following the third section, and the controller (1110, 12000) is further configured to suspend the operation of the first heater based on the third section being determined as the pressure maintaining state and the fourth section being determined as the pressure rising state. a first heater configured to heat a liquid composition accommodated in a liquid storage of a vaporizer (1041, 1130); a puff sensor configured to detect a pressure change in the aerosol generating device (1000, 10000); and a controller (1110, 12000) configured to: determine states of a plurality of sections constituting a puff pattern (400, 500, 600, 700, 800, 900) representing a pressure change over time, based on a signal received from the puff sensor, characterized in that the puff pattern (400, 500, 600, 700, 800, 900) includes a pressure maintaining state, a pressure falling state, and a pressure rising state, and control an operation of the first heater, based on the states of the plurality of sections, determine states of a plurality of sections constituting a puff pattern (400, 500, 600, 700, 800, 900) representing a pressure change over time, based on a signal received from the puff sensor, characterized in that the puff pattern (400, 500, 600, 700, 800, 900) includes a pressure maintaining state, a pressure falling state, and a pressure rising state, and control an operation of the first heater, based on the states of the plurality of sections, wherein the plurality of sections include a first section and a second section following the first section, and the controller (1110, 12000) is further configured to start the operation of the first heater based on the first section being determined as the pressure maintaining state and the second section being determined as the pressure falling state; and wherein the plurality of sections include a third section following the second section and a fourth section following the third section, and the controller (1110, 12000) is further configured to suspend the operation of the first heater based on the third section being determined as the pressure maintaining state and the fourth section being determined as the pressure rising state.