This diploma work aims at roughness and waviness of beechen wood through different ways of treatment, right after hydrothermal modification.. The quality is evaluated by characteristics of rougness and waviness. Chosen factors : hydrothermal monification (Bk0, Bk1, Bk2, Bk3), the ways of editing surface (milling and grounding, P60, P80, P120 and P180) and anatomic direction (perpendicular to the grain and parallel to grain. The work contains 5 chapters. First chapter is dealing with overview of problem-solving, this chapter is also devided to subheads (beechen wood, hydrothermal treatment, termical treatment, roughness, waviness and machining processes). Second chapter contains the aims of the work. Third chapter contains the metodics of the work. Fourth chapter contains the calculations of the work by charts and tables. Fifth chapter is discussion and the last chapter is a conclusion. At the end of the work, we found out, that hydrothermal treatment doesn’t have any effect on roughness and waviness.