For testing electrical properties of packaged
IC devices, there is provided an apparatus which includes a
test board which is located at a testing
station and provided with a plural number of contacting sockets for connecting individual
IC devices to an IC tester separately and independently of each other, a
loader which is located at a loading
station and adapted to feed untested
IC devices toward the
test board, an unloader which is located at an unloading
station and adapted to
discharge tested IC devices from the
test board at the testing station, and a device
transfer mechanism which is movable across the testing station to transfer untested IC devices from the
loader to the test board and also to transfer tested IC devices from the test board to the unloader. Upon detecting completion of a test on one of IC devices in one socket of the test board, a fresh untested IC device is transferred to the testing station to replace the tested IC device. As soon as the fresh IC device is set in position in that socket, execution of a
test program is started with respect to that socket on the test board.