A photonic crystal-based force sensor to measure forces in the wide range 100 nN-10 μN is proposed here. An optimized photonic crystal resonator integrated on top of a Si/SiO2 bilayer cantilever, is used as the sensing device. A sensitivity of 0.1 nm for a force of 100 nN is obtained with a high-quality factor of 10,000. The sensor characteristics in the force ranges 0-1 μN and 0-10 μN are also presented here. Linear wavelength shift and constant quality factor are observed in the entire studied force range.