The 3-20 mum IR thermal emission spectrum of Comet Hale-Bopp = (C/1995 O1) at a heliocentric distance of r_h=1.15 AU has been calculated using fluffy aggregates of silicate core-organic refractory mantle interstellar dust as the comet dust model. The principal dust properties, similar to those obtained for other comets, provide good fits to the observation. Our results are significantly different from the common thought that Hale-Bopp is rich in submicron grains. The mean grain masses derived here are two to three orders of magnitude higher than those estimated from the empirical superheat method or from the IR emission modeling both of which use compact silicate/carbon particles. It has been shown that the IR emission alone can not give a reliable dust production rate. We have also modeled the crystalline silicate emission spectrum.