An exposure apparatus for exposing an object to light. The apparatus
includes a camera which captures an image of a mark on the object to
obtain image data corresponding to the image, an extraction section which
extracts an edge position in the image data obtained by differentiating
the image data, a determination section which determines a position of
the mark by comparing the extracted edge position with a template, and a
control section which changes at least one of a parameter used by the
extraction section and a parameter used by the determination section,
based on a result of the comparing by the determination section. The
object to be exposed is positioned based upon the position of the mark
determined by the determination section.