A power supply unit for an aerosol generation device, comprising: a first load configured to heat an aerosol source, a resistance element (Rs) configured to be connected in series to the first load and configured to detect an electric resistance value of the first load, a switch arranged for connecting the resistance element (Rs) in series with the first load, a power supply configured to discharge electricity to the first load; a processing device, wherein: the processing device is configured to perform a first discharging control of discharging electricity from the power supply to the first load in order to generate aerosol, and a second discharging control of discharging electricity from the power supply to a series circuit formed of the first load and the resistance element (Rs) in order to detect the electric resistance value of the first load; characterized in that: in a specific period, other than a period when the first discharging control and the second discharging control are performed, the processing device is configured to perform a third discharging control of discharging electricity from the power supply to the series circuit in order to evaporate water in a vicinity of the first load; the processing device is configured to perform the third discharging control after the power supply unit is activated; and the processing device is configured to control a time duration of performing the third discharging control based on an elapsed time between a time point when aerosol generation of a last time is ended and a time point when the third discharging control is started. a first load configured to heat an aerosol source, a resistance element (Rs) configured to be connected in series to the first load and configured to detect an electric resistance value of the first load, a switch arranged for connecting the resistance element (Rs) in series with the first load, a power supply configured to discharge electricity to the first load; a processing device, wherein: the processing device is configured to perform a first discharging control of discharging electricity from the power supply to the first load in order to generate aerosol, and a second discharging control of discharging electricity from the power supply to a series circuit formed of the first load and the resistance element (Rs) in order to detect the electric resistance value of the first load; characterized in that: in a specific period, other than a period when the first discharging control and the second discharging control are performed, the processing device is configured to perform a third discharging control of discharging electricity from the power supply to the series circuit in order to evaporate water in a vicinity of the first load; the processing device is configured to perform the third discharging control after the power supply unit is activated; and the processing device is configured to control a time duration of performing the third discharging control based on an elapsed time between a time point when aerosol generation of a last time is ended and a time point when the third discharging control is started. the processing device is configured to perform a first discharging control of discharging electricity from the power supply to the first load in order to generate aerosol, and a second discharging control of discharging electricity from the power supply to a series circuit formed of the first load and the resistance element (Rs) in order to detect the electric resistance value of the first load; characterized in that: in a specific period, other than a period when the first discharging control and the second discharging control are performed, the processing device is configured to perform a third discharging control of discharging electricity from the power supply to the series circuit in order to evaporate water in a vicinity of the first load; the processing device is configured to perform the third discharging control after the power supply unit is activated; and the processing device is configured to control a time duration of performing the third discharging control based on an elapsed time between a time point when aerosol generation of a last time is ended and a time point when the third discharging control is started. in a specific period, other than a period when the first discharging control and the second discharging control are performed, the processing device is configured to perform a third discharging control of discharging electricity from the power supply to the series circuit in order to evaporate water in a vicinity of the first load; the processing device is configured to perform the third discharging control after the power supply unit is activated; and the processing device is configured to control a time duration of performing the third discharging control based on an elapsed time between a time point when aerosol generation of a last time is ended and a time point when the third discharging control is started.