In an image processing apparatus, when an output image generator generates an output image in which an individual image of each part of a product model is arranged around a parts assembly image of the entire product model with a specific part highlighted, a boundary information calculator calculates boundary information for each part highlighted. An individual image arrangement calculator obtains a center position of the highlighted part on the parts assembly image based on the boundary information, obtains a straight line dividing the parts assembly image to equally distribute the parts into respective areas, and calculates a position of arrangement of the individual image of each part corresponding to the highlighted part distributed in each of the areas. The output image generated by the output image generator includes a leading line extending from the individual image of each part to the corresponding part on the parts assembly image.