An aerosol generation device comprising: a power supply unit; and a heater configured to heat an aerosol source; wherein the power supply unit is characterized by comprising: an internal power supply configured to hold power supplied to the heater; a connector connectable to an external power supply; a controller configured to control power supply from the internal power supply to the heater; a first transistor of a dropper method positioned on a first power supply path between the connector and a positive electrode of the internal power supply; a circuit board mounted with the controller and including ground; and a current detection circuit (14, 17) configured to detect at least one of a first current flowing from a negative electrode of the internal power supply at the time of charging the internal power supply and a second current flowing into the negative electrode of the internal power supply at the time of discharging from the internal power supply, wherein a current from the connector is supplied to a source of the first transistor, and a current from a drain of the first transistor is supplied to the positive electrode of the internal power supply, the controller is configured to control a voltage of a gate of the first transistor by feedback based on a current or a voltage supplied from the first transistor to adjust power supplied from the external power supply to the internal power supply, and the negative electrode of the internal power supply is not connected to the ground of the power supply unit, and the controller is configured to control the first transistor to stop the at least one of the first current and the second current in response to the at least one of the first current and the second current exceeding a threshold. a power supply unit; and a heater configured to heat an aerosol source; wherein the power supply unit is characterized by comprising: an internal power supply configured to hold power supplied to the heater; a connector connectable to an external power supply; a controller configured to control power supply from the internal power supply to the heater; a first transistor of a dropper method positioned on a first power supply path between the connector and a positive electrode of the internal power supply; a circuit board mounted with the controller and including ground; and a current detection circuit (14, 17) configured to detect at least one of a first current flowing from a negative electrode of the internal power supply at the time of charging the internal power supply and a second current flowing into the negative electrode of the internal power supply at the time of discharging from the internal power supply, wherein a current from the connector is supplied to a source of the first transistor, and a current from a drain of the first transistor is supplied to the positive electrode of the internal power supply, the controller is configured to control a voltage of a gate of the first transistor by feedback based on a current or a voltage supplied from the first transistor to adjust power supplied from the external power supply to the internal power supply, and the negative electrode of the internal power supply is not connected to the ground of the power supply unit, and the controller is configured to control the first transistor to stop the at least one of the first current and the second current in response to the at least one of the first current and the second current exceeding a threshold. an internal power supply configured to hold power supplied to the heater; a connector connectable to an external power supply; a controller configured to control power supply from the internal power supply to the heater; a first transistor of a dropper method positioned on a first power supply path between the connector and a positive electrode of the internal power supply; a circuit board mounted with the controller and including ground; and a current detection circuit (14, 17) configured to detect at least one of a first current flowing from a negative electrode of the internal power supply at the time of charging the internal power supply and a second current flowing into the negative electrode of the internal power supply at the time of discharging from the internal power supply, wherein a current from the connector is supplied to a source of the first transistor, and a current from a drain of the first transistor is supplied to the positive electrode of the internal power supply, the controller is configured to control a voltage of a gate of the first transistor by feedback based on a current or a voltage supplied from the first transistor to adjust power supplied from the external power supply to the internal power supply, and the negative electrode of the internal power supply is not connected to the ground of the power supply unit, and the controller is configured to control the first transistor to stop the at least one of the first current and the second current in response to the at least one of the first current and the second current exceeding a threshold.