A substrate working device including: an imaging device configured to image a substrate; a memory device configured to memorize various information; and an image processing device configured to perform, when specified work is performed with respect to multiple substrates, for a leading substrate, leading-substrate processing of performing imaging processing for detecting a specified detection target required for the specified work with respect to a leading image obtained by imaging the leading substrate using the imaging device, acquiring region information related to a region in the leading image in which the detection target was detected, and memorizing the region information in the memory device, and, for subsequent substrates except for the leading substrate, subsequent-substrate processing of setting a partial processing region in a subsequent image of the subsequent substrate captured by the imaging device based on the region information, and performing the image processing with respect to the set processing region.