A test apparatus tests a device under test. The test apparatus includes a period generator that generates a rate signal determining a test period according to an operating period of the device under test, a phase comparing section that inputs an operational clock signal for the device under test generated from the device under test and detects a phase difference between the operational clock signal and the rate signal using the rate signal as a standard, a test signal generating section that generates a test signal to be supplied to the device under test in synchronization with the rate signal, a delaying section that delays the test signal in accordance with the phase difference to substantially synchronize the delayed signal with the operational clock signal, and a test signal supplying section that supplies the delayed test signal to the device under test.