A power supply apparatus of this invention includes a communication unit that performs transmission of power and transmission/reception of information, in a non-contact manner, a plurality of object sensors that are provided on a placing table, and generate object detection signals, a determiner that determines, based on identification information of the electronic device acquired by the communication unit, whether or not the detection signals from the object sensors are within predetermined reference value ranges, a power supply unit that supplies power to the electronic device if it is determined that the detection signals are within the reference value ranges, and a controller that uses signals from object sensors that have not detected placement of the electronic device for detecting extraneous object, and that controls the power supply unit based on whether or not an extraneous object is detected.