An exposure apparatus includes a light source unit which emits an exposure light beam; and an illumination system which includes a splitting optical system splitting the exposure light beam emitted from the light source unit into a first exposure light beam and a second exposure light beam, and which illuminates a first pattern with the first exposure light beam and illuminates a second pattern with the second exposure light beam; wherein a predetermined area on a substrate is multiply exposed by radiating the first exposure light beam from the first pattern and the second exposure light beam from the second pattern onto the predetermined area on the substrate.