Method for continuous electrical testing throughout identification of lot and test tray

A method for continuous electrical testing throughout an identification of a lot and a test tray is provided to enhance the uptime of a tester and to reduce the number of testers. A plurality of lots are continuously loaded on a handler(H100). Semiconductor devices of the lots are transferred from a customer tray to a test tray by using a loader of the handler. The identification information on each semiconductor device of the test tray is stored in the handler and transmitted to a server connected with a tester(H110). An electrical test is started on the semiconductor device in the handler and tester by using the identification information(T110).