There are various high-temperature treatment methods for wood. In the "Bois Perdure" process, the thermal treatment of wood is carried out in a furnace by contacting it with hot combustion gases over 200 degrees C without the addition of any chemicals in order to improve its dimensional stability and durability. The treatment eliminates free and bound water in the wood and modifies its molecular structure. In this study, a mathematical model describing the industrial furnace has been developed. The overall model consists of a 3-D unsteady-state sub-model which solves for the flow, heat, and mass transfer in the gas coupled with a 1-D unsteady-state sub-model which calculates the heat and mass transfer in the wood. The 3-D gas sub-model was developed using the commercial CFD code CFX. The 1-D wood sub-model is based on the solution of simultaneous heat and mass transfer equations (Luikov equations) using the implicit finite difference formulation. The model predicts the temperature and moisture distributions in the wood as well as the flow, heat, and moisture profiles in the gas. The model results are compared with the data obtained from the industrial furnace, and a good agreement was found between them.