A transport and epitaxy model to describe silicon epitaxial film growth in a SiHCl 3H 2 system under atmospheric pressure is developed by numerical calculations and comparison with experiments. The rate of epitaxial growth is calculated by computing the transport of momentum, heat and chemical species in a reactor incorporating chemical reactions at a substrate surface described by the Eley-Rideal model. The reaction processes determining the growth rate consist of chemisorption of SiHCl 3 and decomposition by H 2, rate constants of which are evaluated from the model and measured results. The state of the surface during the epitaxial growth is also discussed considering the intermediate species, elementary reactions and rate-limiting processes. The epitaxial growth rate is able to be predicted by the model in this study over wide growth conditions of the species concentrations and the temperatures.