A test device is provided for testing a bottom chip of a package-on-package (PoP) stacked-chip. An upper surface of the bottom chip has a plurality of soldering points for electrically connecting a plurality of corresponding soldering points of a top chip of the PoP stacked-chip. The test device includes a test head and a plurality of test contacts. The test head has the top chip installed inside. The plurality of test contacts is installed on a lower surface of the test head and electrically connected to the plurality of corresponding soldering points of the top chip inside the test head. When the lower surface of the test head contacts the upper surface of the bottom chip, the plurality of test contacts is electrically connected to the plurality of soldering points for testing the bottom chip.