A securing device for a plug unit configured to automatically establish a secured state when the plug unit is plugged in includes an engagement element configured to automatically trigger the secured state through an engagement when the plug unit is plugged in, the automatically established secured state corresponding to a first stable position of the securing device, and an actuatable releasing device configured to unplug the plug unit. The actuatable releasing device is configured to actuate so as to undo the secured state and move the securing device into a second stable position. An unplugging and plugging in of the plug unit enables the securing device to move out of the second stable position.