A manufacturing device has a manufacturing cell for processing workpieces, with a laterally circumferential safety partition, in which a lock is formed for performing a loading operation of the workpieces, wherein a first light barrier arrangement is formed at the lock, and with a driverless conveyor with a load receiver for conveying the workpieces. For performing the loading operation, a second light barrier arrangement and a third light barrier arrangement are formed between the conveyor and the lock, so that the load receiver and the workpieces are laterally bounded on opposite sides by the second light barrier arrangement and by the third light barrier arrangement.