To solve the problem wherein a processing load is increased when performing frequency analysis in each speed range in order to detect low-speed and high-speed moving objects highly accurately respectively, in a moving body detection device utilizing a Doppler signal.

Filter parts 320, 322 extract data in a corresponding frequency band classified by the high/low speed of the moving object from a received signal, respectively. Data corresponding to the high speed to the number of N acquired in a prescribed time frame are inputted into a synthesis part 340. As for data corresponding to the low speed, data to the number of N determined by thinning out data acquired in a longer time frame than the data corresponding to the high speed are taken out and input into the synthesis part 340. The synthesis part 340 performs frequency shift processing, and moves a frequency spectrum of the data corresponding to the low speed to a domain not overlapped with a frequency spectrum of the data corresponding to the high speed. Thereafter, the data in both speed areas are added mutually, and frequency analysis is performed by using acquired data to the number of N.