In proximity x‐ray lithography (XRL), two types of illumination are used: full field and scanning. We describe a single mirror condenser for XRL beam lines which provides a high flux of soft x rays. The surface is generally aspheric, designed using numerical methods, and described by polynomials. The flexible design approach can be used to find a result with specific imaging characteristics according to the various requirements of the beam line, and thus is of more general application. The performance of the designed condenser is verified with ray tracing. For advanced submicron applications, mirror scanning is preferred because of its higher scanning speed. However, with figured mirrors, a small change of grazing angle may cause a large variation of image shape, so that to provide a uniform beam, the scanning of the mirror is compensated by a lateral shift. A uniform exposure of 50×50 mm2field can be achieved.