Ultra-narrow linewidth, angle insensitive guide-mode resonance filter (GMRF) has been designed. The aimed performance on the behavior of the filter with respect to the angular divergence of the incident beam was considered. Results show that high reflection (more than 99.9%) can be obtained at the resonance wavelength, the full-width at half maximum (FWHM ) of TE-polarized light is only 1.1×10 -3 μm, and its sideband reflectance from 0.565 to 0.625 μm is less than 1%. In contrast to the ordinary GMRF, where the location of the resonances is incident angle dependent, it is demonstrated that the maximum peaks of the reflected spectrum gradually decreases with respect to the incident angle, but the reflectance peak position does not change.