A receiving device includes a reception unit that samples a sample signal from a DUT 2; an FFT processing unit 21 that performs an FFT process by multiplying the sample signal by a window function; an FFT length setting unit 34 that, when the signal length of the signal to be measured is shorter than the first FFT length conforming to the communication standard, instead of the first FFT length, sets a second FFT length shorter than the signal length of the signal to be measured, as an FFT length of the FFT process; and a window function setting unit 35 that, when the signal length of the signal to be measured is shorter than the first FFT length, instead of a first window function, sets an asymmetric second window function having a peak separated from a center of a window section, as the window function.