An exposure apparatus includes a projection optical system by which an image of a pattern is projected onto a substrate to expose the substrate. The apparatus also includes a liquid supply system having a supply port from which a liquid is supplied to a space under the projection optical system. A supply amount of the liquid per unit time from the supply port is changed without stopping the liquid supply from the supply port, and the supply amount of the liquid per unit time from the supply port in a first operation is different from the supply amount of the liquid per unit time from the supply port in a second operation that is different from the first operation.