A radar image processing device includes: an estimation unit 1 for setting, as a target pixel, each pixel of a two-dimensional map image, and estimating to which type each target pixel belongs among a pixel caused by the main lobe, a pixel due to the sidelobe, and any other pixel; a pixel value replacement unit 2 for replacing the pixel value of the pixel caused by the main lobe and the pixel value of the pixel due to the sidelobe with pixel values generated in pixel value interpolation processing based on the type of each pixel estimated by the estimation unit 1 to generate a first corrected image; a speckle noise suppression unit 3 for applying speckle noise suppression processing to the first corrected image to generate a second corrected image; and an output image generation unit 4 for generating an output image, in which speckle noise and sidelobes are suppressed, by using the two-dimensional map image, the second corrected image, and the type of each pixel.