An improved Fresnel waveguide lens is presented. It not only exhibits theoretically excellent focusing characteristics and has almost the same efficiency as that of ideal Fresnel lens, but also simplifies the mask process. We give experimental results concerning these lenes (f/D = 5, 2mm aperture) in silicon nitride waveguides. Nearly diffraction limited focusing characteristics and high efficiency (60%) were experi mentally obtained. The experiment results are in good agrement with theoretical analysis.