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 image data which is obtained by imaging a region to be inspected on said substrate and stored in an image storing memory by said imaging part to a plurality of image processing memories; a plurality of image processing parts for performing inspection processes for defect detection on image data corresponding to respective regions to be processed thereby, out of 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 controlling said plurality of image processing parts in accordance with said inspection tasks, respectively, independently of image transfer by said image transfer part.