An image processing apparatus for wafer inspection tool that is able to perform continuously cell to cell comparison inspection, die to die comparison inspection, and cell-to-cell and die-to-die hybrid comparison inspection, employing a plurality of processors. This image processing apparatus for wafer inspection tool comprises a plurality of processors for performing parallel processing, means for cutting out image data including a forward end overlap and a rear end overlap at partition boundaries in order to cut serial data into a predetermined image size, means for distributing the cutout image data to the plurality of processors, and means for assembling results of processing performed by the plurality of processors. The forward end overlap is set greater than a pitch of the cell subject to cell to cell comparison inspection.