1. An appearance inspection apparatus for detecting a defect of a pattern on the basis of an image of a surface of a substrate on which said pattern is formed, which is captured by an imaging part, comprising: an image transfer part for transferring an image data, which is obtained by imaging a region to be inspected on said substrate and which is stored in an image storing memory by said imaging part, wherein said image data includes data corresponding to a plurality of divided regions which are obtained by dividing said regions, said image data being transferred in its totality to each of a plurality of image processing memories; a plurality of image processing parts for performing inspection processes for defect detection on a respective part of said plurality of divided regions corresponding to respective regions to be processed thereby, out of said plurality of divided regions included in transferred image data which are transferred to said image processing memories by said image transfer part; and a plurality of image processing control parts for acquiring inspection tasks each prescribing inspection details, and associating said image processing part and said part of said plurality of divided regions to be inspected and controlling said plurality of image processing parts in accordance with said inspection tasks, respectively, independently of image transfer by said image transfer part; wherein said image processing control parts examine a same contents data comprising said image data to determine whether or not said part of said plurality of divided regions to be inspected by said image processing parts are included in said transferred image data which are transferred to said image processing memories, and when no image data to be inspected is included, said image processing control parts cause the image processing parts to wait until said image data including said plurality of divided regions to be inspected by said image processing arts are transferred to said image processing memories.