A high voltage power supply device has a plurality of battery modules connected to each other in series by coupling a safety plug unit to a safety plug unit connecting base to output a series voltage from a power supply output coupler. The safety plug unit connects/disconnects electrode terminals of all the battery modules to each other. Female electrode bodies electrically connected to power supply terminals of the respective battery modules are collectively positioned in a limited area and are arranged at equal intervals on the safety plug unit connecting base. An output voltage of each battery module is set to be lower than 50V to reduce the risk of injury during use, inspection or maintenance of the high voltage power supply device and to downsize the device.