There is disclosed a general-purpose APD measurement apparatus capable of changing a measurement condition, such as the number of channels or a resolution bandwidth (RBW) in compliance with a standard for the subject of measurement, measuring various subjects of measurement, and correcting measurement equipment, thereby enabling a higher accuracy of measurement. The resolution bandwidth (RBW) or the number of channels when measurement is performed can be flexibly changed by controlling the cycle of a clock signal whose data are sampled by A/D conversion means 110, frequency selection means 130, and an APD unit 300. The frequency selection means 130 includes FFT type processing means 131 and filter bank type processing means 132 arranged in parallel. The output of FFT type processing means 131 is corrected based on the output of the filter bank type processing means 132 with a high accuracy of measurement. Accordingly, a higher accuracy of measurement is made possible.