Mechano-sorptive tests in climatic chamber have been performed on unmodified and thermally modified wood by using 3-points bending test. The specimens were cut by splitting to get a straight grain. A geometrical configuration, with a small thickness was chosen to speed-up the moisture steady state (moisture equilibrium) within the sample. Then the samples were loaded at 10% of their average of rupture load. Average elastic modulus of the samples, as well as the average bending strength were determined on another set of samples coming from the same board. The tests were performed in a climate chamber, where the relative humidity can be changed between 35% and 80%. Three level of relative humidity have been tested (45%, 55%, and 65%) following three cycles. The average initial relative humidity was 55%, and the samples were loaded after equilibrium at their relative humidity level is reached. After 19 h of creep the relative humidity was changed to 65% (during two cycles), then 45% after 65 h. The results obtained show a more pronounced impact of humidity on non-thermally modified wood compared to thermally modified wood. Additionally, the measured elastic displacement is greater in non-thermally modified wood than in thermally modified wood. These results demonstrate that thermally modified wood exhibits significantly better physico-mechanical characteristics than unmodified wood.