A radar image processing device, comprising: a refocusing unit for inputting a radar image and changing a focus of the radar image, the radar image being a SAR image; a ghost image determination unit for determining a pixel including a ghost image from the radar image the focus of which has been changed by the refocusing unit, the ghost image being an ambiguity; and a ghost image suppression unit for changing a value of the pixel that has been determined by the ghost image determination unit to include the ghost image on the radar image the focus of which has been changed by the refocusing unit, characterized in that the radar image processing device further comprises a normalization unit for normalizing a pixel amplitude in the radar image by replacing the amplitude of all pixels with a constant value that is different from zero, wherein the refocusing unit changes the radar image, the pixel amplitude of which is normalized by the normalization unit, so as to generate an image focused on an imaging area that corresponds to each of multiple candidates for a number of foldings M and N, where M denotes a shift by an integer multiple of the pulse repetition interval of the radar at reception time and N denotes the number of foldings that indicates the degree of aliasing of azimuth ambiguity, and the ghost image determination unit specifies estimated values M 0 and N 0 of the number of foldings that are determined on the basis of these images as information related to the focus that reduces the blur of the ghost image and determines the pixel including the ghost image on a basis of the specified information related to the focus. a refocusing unit for inputting a radar image and changing a focus of the radar image, the radar image being a SAR image; a ghost image determination unit for determining a pixel including a ghost image from the radar image the focus of which has been changed by the refocusing unit, the ghost image being an ambiguity; and a ghost image suppression unit for changing a value of the pixel that has been determined by the ghost image determination unit to include the ghost image on the radar image the focus of which has been changed by the refocusing unit, characterized in that the radar image processing device further comprises a normalization unit for normalizing a pixel amplitude in the radar image by replacing the amplitude of all pixels with a constant value that is different from zero, wherein the refocusing unit changes the radar image, the pixel amplitude of which is normalized by the normalization unit, so as to generate an image focused on an imaging area that corresponds to each of multiple candidates for a number of foldings M and N, where M denotes a shift by an integer multiple of the pulse repetition interval of the radar at reception time and N denotes the number of foldings that indicates the degree of aliasing of azimuth ambiguity, and the ghost image determination unit specifies estimated values M 0 and N 0 of the number of foldings that are determined on the basis of these images as information related to the focus that reduces the blur of the ghost image and determines the pixel including the ghost image on a basis of the specified information related to the focus.