Research were carried out on thermal modified beech wood. The first step it was determination of thermal treatment parameters. In the next step chosen mechanical and physical properties were determined such as: wood density, compression strength along fibers, bending strength, modulus of elasticity, linear shrinkage, linear swelling, equilibrium moisture point for normal conditions and color. Increase of compression strength along fibers and modulus of elasticity was observed. As a result of thermal treatment was reduction of shrinkage in tangential direction. Equilibrium moisture point for normal conditions was les for thermal modified wood. Overall darkening of wood occurred after thermal treatment.