Abstract: A test apparatus configured to test a device under test includes a power supply and a power compensation circuit. The power supply is configured to supply electric power to a power supply terminal of the device under test via a first route or a second route that are connected in parallel. The first route includes a first switch element configured to be controlled according to a first control signal. The power compensation circuit is located on the second route, wherein the power compensation circuit includes a second switch element configured to be controlled according to a second control signal, the power compensation circuit is configured to generate a compensation pulse current when the first switch element is turned off and the second switch element is turned on.