We designed and fabricated guided-mode resonance filters (GMRFs) with a wedged waveguide layer, and analyzed their spectral characteristics. GMRF was etched for several times with the ion-beam etching technique and a triangle-shaped mask to obtain a wedged waveguide layer. The lines of photoresist gratings and thickness variation direction of the wedge-shaped waveguide layer are either parallel or perpendicular to each other. The experimental results show that the relationship between the resonance peak wavelength and position on the filter is approximately linear for the two samples. The half width at maximum in the case that the grating lines are parallel to the thickness variation direction of the wedge-shaped waveguide layer is larger than that in the case that the grating lines are perpendicular to the thickness variation direction. Through a linear gradation in the thickness of the Ta2O5 film across a distance of 20 mm, the spectral location of the reflection peaks was found to vary nearly linearly across the spectral range of 1560-1600 nm.