According to one embodiment, an information processor, which is capable of supplying power to an external device, includes a connector, a storage module, and a power supply control module. The connector connects the external device to the information processor. The storage module stores a plurality of power supply modes each defining conditions of respective modules of the information processor to make the external device connected to the connector chargeable. The power supply control module selects a power supply mode effective for the external device from the power supply modes when the external device is connected to the connector, and sets the respective modules of the information processor according to the conditions corresponding to the power supply mode selected.