A test chip socket comprises a contact block fixed to a tester substrate, a tray mounted to the contact block, the tray having a convex part for positioning test target chips to a plurality of mount positions, and a plurality of probes each of which is held by the contact block and contacts the tester substrate and the test target chip, wherein each probe contacts with a terminal of each test target chip mounted to the mounting position when the tray mounting the plurality of the test target chip is fixed to the contact block.