1. A test apparatus that tests a device under test, comprising: a vector expanding section that sequentially generates a plurality of test vectors to be supplied to the device under test in a prescribed order; a predicting section that (i) calculates a predicted value for each test vector by simulating an operation of the device under test, the predicted value indicating a prescribed characteristic value of the device under test to be measured while the device under test is supplied with a test signal corresponding to the test vector, (ii) calculates normalized predicted values by dividing each predicted value by a predicted value corresponding to a reference test vector, and (iii) calculates, for each test vector, a prediction variation value indicating a variation amount between the normalized predicted value corresponding to the test vector and the normalized predicted value corresponding to the test vector supplied to the device under test immediately prior to the above test vector; a measuring section that (i) obtains a measured value for each test vector by measuring the prescribed characteristic value of the device under test each time the device under test is supplied with a test vector, (ii) calculates normalized measured values by dividing each measured value by a measured value corresponding to the reference vector, and (iii) calculates, for each test vector, a measurement variation value indicating a variation amount between the normalized measurement value corresponding to the test vector and the normalized measurement value corresponding to the test vector supplied to the device under test immediately prior to the above test vector; and a judging section that judges whether the device under test is defective based on a ratio between the prediction variation value and the measurement variation value corresponding to each test vector.