A method of manufacturing a semiconductor device may include, but is not limited to the following processes. A first group identifier allocated to a first group of semiconductor wafers is detected. The first group of semiconductor wafers includes a first semiconductor wafer to be processed first among the first group. A first processor of a plurality of processors, which process respective ones of the first group of semiconductor wafers, are determined based on the first group identifier. The first processor is used for processing the first semiconductor wafer. The first semiconductor wafer is supplied to the first processor.