The error of a measurement system can be corrected even if the frequency of an input signal of a device under test is different from that of the output signal. A signal output acquiring section acquires the power of the input signal by a power meter not shown in the drawing. Thus, errors due to frequency tracking can be separated depending on the direction in a signal flow graph. Since a receiver measures the parameter concerning the received signal when a signal source is directly connected to a receiver, the measurement system error factor of the receiver can be acquired. The parameter of a device under test can be measured while the error is corrected when the results of measurement, concerning the device under test of receivers are combined.