A passive radar device, comprising: an antenna for direct-wave reception for receiving a direct wave that directly arrives after being transmitted from a radio source; an antenna for scattered-wave reception for receiving a scattered wave transmitted from the radio source and scattered by a target; characterized by a direct-wave reception unit for dividing a received signal of the direct wave into a plurality of H blocks, and dividing each of the block into a plurality of N pulses; a scattered-wave reception unit for dividing a received signal of the scattered wave into a plurality of H blocks, and dividing each of the blocks into a plurality of N pulses; wherein a pulse width is T0, a block width is Tb, Tb=NT0; a pulse-by-pulse range compression unit for executing cross-correlation processing between the received signal of the direct wave and the received signal of the scattered wave on each of the divided pulses and calculating a pulse-by-pulse range profile; a block-by-block Doppler processing unit being as a first Doppler processing unit for calculating a first Doppler frequency spectrum by executing pulse-direction Fourier transform on the pulse-by-pulse range profile output from the pulse-by-pulse range compression unit for the plurality of H blocks each of which groups the plurality of N pulses; a Doppler frequency cell-associated range migration compensation unit for compensating a range-direction movement amount on the first Doppler frequency spectrum output from the block-by-block Doppler processing unit corresponding to each of a plurality of Doppler frequency cells in each block, wherein a Doppler-frequency-cell is the frequency domain corresponding to a pulse of the time domain; and a block-direction Doppler processing unit being as a second Doppler processing unit for calculating a second Doppler frequency spectrum by executing block-direction Fourier transform block-by-block on an output from the Doppler frequency cell-associated range migration compensation unit. an antenna for direct-wave reception for receiving a direct wave that directly arrives after being transmitted from a radio source; an antenna for scattered-wave reception for receiving a scattered wave transmitted from the radio source and scattered by a target; characterized by a direct-wave reception unit for dividing a received signal of the direct wave into a plurality of H blocks, and dividing each of the block into a plurality of N pulses; a scattered-wave reception unit for dividing a received signal of the scattered wave into a plurality of H blocks, and dividing each of the blocks into a plurality of N pulses; wherein a pulse width is T0, a block width is Tb, Tb=NT0; a pulse-by-pulse range compression unit for executing cross-correlation processing between the received signal of the direct wave and the received signal of the scattered wave on each of the divided pulses and calculating a pulse-by-pulse range profile; a block-by-block Doppler processing unit being as a first Doppler processing unit for calculating a first Doppler frequency spectrum by executing pulse-direction Fourier transform on the pulse-by-pulse range profile output from the pulse-by-pulse range compression unit for the plurality of H blocks each of which groups the plurality of N pulses; a Doppler frequency cell-associated range migration compensation unit for compensating a range-direction movement amount on the first Doppler frequency spectrum output from the block-by-block Doppler processing unit corresponding to each of a plurality of Doppler frequency cells in each block, wherein a Doppler-frequency-cell is the frequency domain corresponding to a pulse of the time domain; and a block-direction Doppler processing unit being as a second Doppler processing unit for calculating a second Doppler frequency spectrum by executing block-direction Fourier transform block-by-block on an output from the Doppler frequency cell-associated range migration compensation unit.