A disparity deriving apparatus (3) for deriving disparity of an object based on a reference image of the object captured at a first image capturing position and a comparison image of the object captured at a second image capturing position includes a calculator (310) to calculate costs between a first reference area in the reference image and each one of corresponding areas corresponding to the first reference area in a given region in the comparison image, and costs between a second reference area, surrounding the first reference area in the reference image, and each one of corresponding areas corresponding to the second reference area in a given region in the comparison image; a synthesizer (320) to synthesize the costs of the first reference area, and the costs of the second reference area as synthesis costs; a deriving unit (330)to derive a disparity value of the object captured in the first reference area based on the synthesis costs synthesized by the synthesizer; and a correction unit (340) to apply a spatial filter to a local region, composed of a plurality of areas, in the first reference image to correct a disparity value of the local region.