PURPOSE: To provide a highly safe secondary battery charging device used for portable electronic device by solving such a problem that a secondary battery is overcharged due to the continuous flow of an electric current which is made to flow for confirming the connection between the output terminal of the charging device and the secondary battery.

CONSTITUTION: The connection between a secondary battery and the output terminal of a charging device can be confirmed by only making an electric current to flow to the secondary battery for several seconds only immediately after the secondary battery is connected to the charging device when a mounting state detecting means 12 which detects that the secondary battery is mounted on the charging device, opening/closing means 14 which is connected to a current outputting means 4 and closes a circuit for several seconds only after the secondary battery is mounted on the charging device, and storing means 15 which stores the output signal of a comparing means 7 when the opening/closing means 14 is closed are added to the conventional charging device.