A power supply unit for an aerosol inhaler that causes an aerosol generated from an aerosol source to pass through a flavor source to add a flavor component of the flavor source to the aerosol, the power supply unit comprising: a power supply configured to be dischargeable to a first load configured to heat the aerosol source; and a processing device, wherein the processing device is configured to control discharging from the power supply to the first load in response to a signal from a sensor configured to output the signal indicating an aerosol generation request, wherein the processing device is configured to control the discharging from the power supply to the first load such that a unit flavor amount converges to a target amount based on an output of an element configured to output information on a temperature of the flavor source, the unit flavor amount being an amount of a flavor component added to an aerosol generated for each aerosol generation request, wherein the power supply is configured to be dischargeable to a second load configured to heat the flavor source, characterized in that the processing device is configured to determine, based on an output of the element, a first power that needs to be discharged from the power supply to the first load in order to cause the unit flavor amount to converge to the target amount, configured to cause the first power to be discharged from the power supply to the first load when the first power is equal to or smaller than a first threshold, and configured to cause power to be discharged from the power supply to the second load and cause power equal to or smaller than the first threshold to be discharged from the power supply to the first load when the first power is larger than the first threshold, or the processing device is configured to determine, based on an output of the element, a first power that needs to be discharged from the power supply to the first load in order to cause the unit flavor amount to converge to the target amount, and configured to cause power discharged from the power supply to the second load to be increased and cause power equal to or smaller than a first threshold to be discharged from the power supply to the first load when the first power is larger than the first threshold. a power supply configured to be dischargeable to a first load configured to heat the aerosol source; and a processing device, wherein the processing device is configured to control discharging from the power supply to the first load in response to a signal from a sensor configured to output the signal indicating an aerosol generation request, wherein the processing device is configured to control the discharging from the power supply to the first load such that a unit flavor amount converges to a target amount based on an output of an element configured to output information on a temperature of the flavor source, the unit flavor amount being an amount of a flavor component added to an aerosol generated for each aerosol generation request, wherein the power supply is configured to be dischargeable to a second load configured to heat the flavor source, characterized in that the processing device is configured to determine, based on an output of the element, a first power that needs to be discharged from the power supply to the first load in order to cause the unit flavor amount to converge to the target amount, configured to cause the first power to be discharged from the power supply to the first load when the first power is equal to or smaller than a first threshold, and configured to cause power to be discharged from the power supply to the second load and cause power equal to or smaller than the first threshold to be discharged from the power supply to the first load when the first power is larger than the first threshold, or the processing device is configured to determine, based on an output of the element, a first power that needs to be discharged from the power supply to the first load in order to cause the unit flavor amount to converge to the target amount, and configured to cause power discharged from the power supply to the second load to be increased and cause power equal to or smaller than a first threshold to be discharged from the power supply to the first load when the first power is larger than the first threshold.