A test apparatus for efficiently and accurately testing a high frequency voltage dependency of an impedance of a test object without damaging the test object. The test apparatus includes a high frequency power source unit, a reference waveform generator, a matching device, an oscilloscope, a control panel, and a main control unit. The test apparatus may boost a high frequency pulse output at a relatively low power from the high frequency power source unit to a voltage required for a high frequency withstand voltage test to be applied to a test object in a state where impedance matching is performed between the high frequency power source unit and the test by the matching device, that is, under a tuned state. Whether the waveform of the voltage applied to the test object is a defined waveform may be concisely monitored and observed by the oscilloscope.