A test apparatus for testing a semiconductor device having contact pads on its top and its back, and to a method for testing the semiconductor device is disclosed. In one embodiment, the test apparatus has a test socket which is mounted on a test printed circuit board. Internal through-contact elements of the test socket can be used to test contact pads on the top of the semiconductor device. The contact pads on the back of the semiconductor device can be connected for the purpose of testing the semiconductor device using external through-contact elements which are arranged outside of the locating seat.