In order to prevent exposure mismatch on a boundary between exposure regions that causes pattern connection defects (including stitch defects), exposure is performed twice or more on a whole exposure region of a glass substrate. The exposure method includes aligning a reticle in a scanning direction, exposing the reticle pattern onto the glass substrate, moving the glass substrate one-half of the width of the reticle, and exposing an exposure area twice by repeating the exposing and moving steps.