To perform a charging operation in a proper case by confirming the voltage and the capacity of an AC adaptor.

The AC adaptor 1 is provided, in such a way that an AC/DC conversion part 11 which converts an AC power supply into a DC power supply is provided and that a voltage-and-capacity-data storage part 12, in which the rated voltage value and the rated capacity value of the DC power supply to be output from the AC/DC conversion part 11 are stored in a predetermined address is provided. The information processor 2 is provided, with the rated voltage value and the rated capacity value of the DC power supply being stored in the AC adaptor 1 are read out, when the AC adaptor 1 is connected, with whether the rated voltage value of the DC power supply being proper as the input voltage of the information processor 2 is determined, with a warning being displayed when the rated voltage value is not proper, with whether the rated capacity value of the AC adaptor 1 is proper as the capacity of the information processor 2 being decided when the rated voltage value is proper, with a warning being displayed when the rated voltage value is not proper, with whether the rated capacity value of the AC adaptor 1 is proper as the capacity of the information processor 2 is decided, when the rated voltage value is proper, with a warning being displayed when the rated capacity value is not proper and with a battery 23 being chargeable, when the rated capacity value is proper.