A proximity X-ray exposure apparatus for irradiating a reticle with X-rays generated from an X-ray source and irradiating a substrate with X-rays that have passed through the reticle. The apparatus includes a plasma X-ray source for generating X-rays by producing plasma, and a control device for controlling X-ray intensity distribution by controlling production of the plasma so that the plasma is produced at a plurality of positions in one irradiating operation of the substrate with the X-rays. The control device controls the X-ray intensity distribution in order to control the plurality of positions so that a required amount of defocusing, which is a size of a projection image corresponding to one point on the reticle formed by irradiating the reticle with X-rays generated at the plurality of positions, can be obtained.