A testing apparatus includes a thermal control chamber including a test room, which temperature is controlled within a testing temperature range; a carrier frame including a direction guiding unit installed securely within the test room and formed with one guiding groove and a carrier rod extending through the guiding groove in the direction guiding unit; and a clamping unit mounted on the carrier rod for clamping a display-panel module securely, wherein, movement of the carrier rod transversely within the guiding groove relative to the direction guiding unit results in disposing the display-panel module to extend along one of several testing directions for undergoing a burn-in test.