A voltage detecting apparatus detects a detected AC voltage generated in a detected object. The voltage detecting apparatus includes a detection electrode that is disposed facing the detected object, and is capacitively coupled to the detected object. The voltage detecting apparatus also includes a bootstrap circuit that operates using a floating power supply generated with a reference voltage, and outputs a detection signal whose amplitude changes in accordance with an AC potential difference between the detected AC voltage and the reference voltage. The voltage detecting apparatus further includes an insulating circuit that inputs the detection signal and outputs an insulated detection signal that is electrically insulated from the detection signal, and a voltage generating circuit that amplifies the insulated detection signal to reduce the AC potential difference and generate the reference signal.