A boost apparatus adapted for providing a direct-current (DC) output voltage to a load is provided, and the boost apparatus includes a boost power conversion circuit and a control chip. The boost power conversion circuit has a diode coupled to the load. Besides, the boost power conversion circuit is configured to receive a DC input voltage and provide the DC output voltage to the load in response to a pulse-width-modulation (PWM) signal. The control chip is coupled to the boost power conversion circuit and configured to generate the PWM signal to control the operation of the boost power conversion circuit. The control chip is also configured to stop outputting the PWM signal and enter into a shutdown state when the diode is an open circuit or a short circuit, so as to protect the boost apparatus and/or the load from being damaged.