A current detection resistor is connected between an output terminal of a high voltage generator and an air motor. A coater current detector detects a coater current supplied to a coater based on a potential difference taking place on both terminals of the current detection resistor. The high-voltage control device serves to discriminate based on the coater current detected by the coater current detector whether the coater is caused to be close to a coating object. When it is discriminated that the coater is caused to be close to the coating object, the high-voltage control device outputs a shut-off signal for shutting off supply of the power supply voltage to the power supply voltage control device.