A refractive beam shaper is designed, which transforms a Gaussian beam profile into a diverging uniform line beam profile, exactly, an elongated super-Gaussian profile. The advantage of our optical system is that the area of uniform illumination can be changed by simply shifting the position of the observation plane without using an additional optical element. Whereas previous refractive beam shapers have been designed to have a specific intensity distribution at a certain position, our refractive beam shaper has been designed to generate a desired intensity and wavefront simultaneously, so that it gives a desired beam profile during propagation. The designed refractive beam shaper generates a uniform line beam with 4 mm beam width at half maximum intensity and a diverging angle of 13.3 deg. Furthermore, we have checked the utility and the stability of the output beam by calculating the changes in the size, the uniformity, and the efficiency of the line beam when it propagates a distance of 960 mm.