A power supply unit for an aerosol inhaler, the power supply unit comprising: a power supply that is able to discharge power to a load for generating an aerosol from an aerosol generation source ; and a control unit that is configured to control at least one of charging and discharging of the power supply such that the power supply does not become one or both of a fully charged state and a discharging termination state, wherein a remainder which is obtained by subtracting an amount of power stored in the power supply to cause the discharging to be prohibited from an amount of power stored in the power supply in a state where the charging is completed is defined as a discharging permission power amount, and characterized in that the control unit controls at least one of the charging and the discharging of the power supply such that the discharging permission power amount becomes equal to or larger than an amount of power required to be supplied to the load in order to empty the aerosol generation source which is unused, in a state where the charging of the power supply is completed and in a second state where a numerical index, indicating a deteriorated state of the power supply and based on calculation of dividing an internal resistance value of the power supply in a deteriorated state by an internal resistance value of the power supply in a brand new state and multiplying the quotient by 100, is equal to or larger than a threshold or a numerical index, indicating a healthy state of the power supply and based on a calculation of dividing a full charge capacity of the power supply in the deteriorated state by a full charge capacity of the power supply in the brand new state and multiplying the quotient by 100, is smaller than a threshold. a power supply that is able to discharge power to a load for generating an aerosol from an aerosol generation source ; and a control unit that is configured to control at least one of charging and discharging of the power supply such that the power supply does not become one or both of a fully charged state and a discharging termination state, a remainder which is obtained by subtracting an amount of power stored in the power supply to cause the discharging to be prohibited from an amount of power stored in the power supply in a state where the charging is completed is defined as a discharging permission power amount, and characterized in that the control unit controls at least one of the charging and the discharging of the power supply such that the discharging permission power amount becomes equal to or larger than an amount of power required to be supplied to the load in order to empty the aerosol generation source which is unused, in a state where the charging of the power supply is completed and in a second state where a numerical index, indicating a deteriorated state of the power supply and based on calculation of dividing an internal resistance value of the power supply in a deteriorated state by an internal resistance value of the power supply in a brand new state and multiplying the quotient by 100, is equal to or larger than a threshold or a numerical index, indicating a healthy state of the power supply and based on a calculation of dividing a full charge capacity of the power supply in the deteriorated state by a full charge capacity of the power supply in the brand new state and multiplying the quotient by 100, is smaller than a threshold. <EOS>