A power supply switching apparatus includes a first switching unit supplying power from a first conductive path to a first output path when the voltage of the first conductive path is greater than the voltage of a second conductive path, and supplies power from the second conductive path to the first output path. A second switching unit 80 supplies power from a fourth conductive path to a second output path when the voltage of a fourth conductive path is greater than the voltage of a third conductive path, and supplies power from the third conductive path to the second output path. An element unit allows a current to flow from the second conductive path to the third conductive path when the voltage of the third conductive path is smaller than the voltage of the second conductive path, and otherwise blocks a current.