An object detecting device for detecting objects in front of a vehicle, on the basis of images of two cameras (112, 113), the object detecting device comprising: a disparity acquisition unit configured to compare individual images of the two cameras (112, 113) and to calculate a disparity for each pixel; a near-far boundary setting unit configured to set a boundary (Rb) between a near-region and a far-region wherein the near-region is closer to the vehicle than the far-region, in a single image of one of the two cameras (112, 113); a near object detecting unit configured to detect an object of the near-region, on the basis of the disparity; a far object detecting unit configured to detect an object of the far-region, on the basis of the single image; characterized in further comprising: a road surface estimation unit configured to calculate a distance to a road surface in front of the vehicle, on the basis of the disparity, and detect a boundary pixel position between a region where reliability of the calculated distance is.high and a region where the reliability of the calculated distance is low, wherein the near-far boundary setting unit is configured to set the boundary (Rb) on the basis of the boundary pixel position, wherein the road surface estimation unit includes: a virtual plane setting unit configured to output a V-Disparity image obtained by projecting, onto a virtual plane where a transverse axis shows the disparity and a longitudinal axis shows a coordinate position of a longitudinal direction of each pixel of the single image, data of the disparity and the coordinate position corresponding to each pixel of the single image; a straight line detecting unit configured to detect a most dominant straight line in the V-Disparity image; and a boundary pixel position detecting unit which is configured to detect the boundary pixel position, on the basis of a deviation of the straight line in the V-Disparity image and a position of the data of the disparity in the V-Disparity image, and more specifically by being configured to confirm a histogram frequency of each pixel which the straight line passes through sequentially from a near side of the vehicle, to detect a first pixel position when pixels, where histogram frequencies become a constant value or less, are continuous by a predefined number or more as the boundary pixel position. a disparity acquisition unit configured to compare individual images of the two cameras (112, 113) and to calculate a disparity for each pixel; a near-far boundary setting unit configured to set a boundary (Rb) between a near-region and a far-region wherein the near-region is closer to the vehicle than the far-region, in a single image of one of the two cameras (112, 113); a near object detecting unit configured to detect an object of the near-region, on the basis of the disparity; a far object detecting unit configured to detect an object of the far-region, on the basis of the single image; characterized in further comprising: a road surface estimation unit configured to calculate a distance to a road surface in front of the vehicle, on the basis of the disparity, and detect a boundary pixel position between a region where reliability of the calculated distance is.high and a region where the reliability of the calculated distance is low, wherein the near-far boundary setting unit is configured to set the boundary (Rb) on the basis of the boundary pixel position, wherein the road surface estimation unit includes: a virtual plane setting unit configured to output a V-Disparity image obtained by projecting, onto a virtual plane where a transverse axis shows the disparity and a longitudinal axis shows a coordinate position of a longitudinal direction of each pixel of the single image, data of the disparity and the coordinate position corresponding to each pixel of the single image; a straight line detecting unit configured to detect a most dominant straight line in the V-Disparity image; and a boundary pixel position detecting unit which is configured to detect the boundary pixel position, on the basis of a deviation of the straight line in the V-Disparity image and a position of the data of the disparity in the V-Disparity image, and more specifically by being configured to confirm a histogram frequency of each pixel which the straight line passes through sequentially from a near side of the vehicle, to detect a first pixel position when pixels, where histogram frequencies become a constant value or less, are continuous by a predefined number or more as the boundary pixel position. a virtual plane setting unit configured to output a V-Disparity image obtained by projecting, onto a virtual plane where a transverse axis shows the disparity and a longitudinal axis shows a coordinate position of a longitudinal direction of each pixel of the single image, data of the disparity and the coordinate position corresponding to each pixel of the single image; a straight line detecting unit configured to detect a most dominant straight line in the V-Disparity image; and a boundary pixel position detecting unit which is configured to detect the boundary pixel position, on the basis of a deviation of the straight line in the V-Disparity image and a position of the data of the disparity in the V-Disparity image, and more specifically by being configured to confirm a histogram frequency of each pixel which the straight line passes through sequentially from a near side of the vehicle, to detect a first pixel position when pixels, where histogram frequencies become a constant value or less, are continuous by a predefined number or more as the boundary pixel position.