An information processing apparatus comprising: an external power supply; a secondary battery; a power supply monitoring circuit; and an information processing unit (20, 21), wherein the information processing unit (20, 21) is operated by electrical power supplied from the external power supply or the secondary battery, and the power supply monitoring circuit includes a first determining unit that is configured to determine whether a voltage supplied from the external power supply is equal to or greater than a voltage threshold, a second determining unit that is configured to determine whether a current supplied from the external power supply is equal to or greater than a current threshold, an electrical power saving control circuit that is configured to drop, when the first determining unit determines that the supplied voltage is lower than the voltage threshold and the second determining unit determines that the supplied current is equal to or greater than the current threshold, electrical power consumed by the information processing unit (20, 21), and an electrical power source switching circuit that is configured to select one of the external power supply and the secondary battery as an electrical power source to the information processing unit (20, 21), based on the supplied voltage, and the electrical power source switching circuit is configured to determine whether the supplied voltage is equal to or greater than a predetermined threshold that is smaller than the voltage threshold, to interrupt, when the supplied voltage is lower than the predetermined threshold, the electrical power supplied from the external power supply to the information processing unit (20, 21), and to supply electrical power from the secondary battery to the information processing unit (20, 21). an external power supply; a secondary battery; a power supply monitoring circuit; and an information processing unit (20, 21), wherein the information processing unit (20, 21) is operated by electrical power supplied from the external power supply or the secondary battery, and the power supply monitoring circuit includes a first determining unit that is configured to determine whether a voltage supplied from the external power supply is equal to or greater than a voltage threshold, a second determining unit that is configured to determine whether a current supplied from the external power supply is equal to or greater than a current threshold, an electrical power saving control circuit that is configured to drop, when the first determining unit determines that the supplied voltage is lower than the voltage threshold and the second determining unit determines that the supplied current is equal to or greater than the current threshold, electrical power consumed by the information processing unit (20, 21), and an electrical power source switching circuit that is configured to select one of the external power supply and the secondary battery as an electrical power source to the information processing unit (20, 21), based on the supplied voltage, and the electrical power source switching circuit is configured to determine whether the supplied voltage is equal to or greater than a predetermined threshold that is smaller than the voltage threshold, to interrupt, when the supplied voltage is lower than the predetermined threshold, the electrical power supplied from the external power supply to the information processing unit (20, 21), and to supply electrical power from the secondary battery to the information processing unit (20, 21).