A memory test is carried out on semiconductor integrated circuit devices including a semiconductor memory at low cost with efficiency. In a test burn-in system, twenty-four test boards are processed in sequence with time differences, and the test boards are circulated one by one. In this case, the memory test is conducted with the sequence of single board processing: the test is started with a test board in which semiconductor integrated circuit devices have been embedded, and semiconductor integrated circuit devices are discharged, beginning with a test board that has undergone the test.