An apparatus includes a plurality of test heads to which probe cards are electrically connected; a wafer tray which is able to hold a semiconductor wafer; and an alignment apparatus which positions the semiconductor wafer held on the wafer tray relatively with respect to the probe card so as to make the wafer tray face the probe card. The wafer tray has a pressure reducing mechanism which pulls the wafer tray toward the probe card. The alignment apparatus is configured to be able to move along the array direction of the test heads.