A transfer method employs a transfer system including a semiconductor handling device and an automatic transfer device. The semiconductor handling device includes a first transfer mechanism and a first optically coupled parallel I/O communications interface. The automatic transfer device includes a second transfer mechanism and a second optically coupled parallel I/O communications interface. The transfer method includes a successive transfer notifying step wherein the automatic transfer device and the semiconductor handling device notify each other that a successive transfer is possible via an optical communications between the first and the second optically coupled parallel I/O communications interface in case where a plurality of objects to be processed are able to be successively transferred one by one between the first and the second transfer mechanism; and a successive transfer step wherein the objects are transferred one by one between the first and the second transfer mechanism.