PURPOSE: To provide a method and device capable of freely performing beautiful two-dimensional cutting for wood which is nonuniform in a cross-sectional shape like a natural log and has size and thickness of some degree and capable of easily working a notch part in a log house.

CONSTITUTION: A rotary cutting tool 1 is so constituted that many cutting teeth are projected in spiral arrangement on the surface of a bar-shaped body and also the central part has slightly large diameter for both end parts of the bar-shaped body. The rotary cutting tool 1 is rotated in a state wherein tensile force in the axial direction is given and cuts the material to be cut. In the case of cutting or cutting-off wood 7 by rotating the rotary cutting tool 1, the direction of rotation of the cutting tool 1 is so reversed properly that cutting always becomes contour turning for the cut end. The rotary cutting tool is equipped with a driving means for synchronously rotating both end parts thereof respectively and with the relative feeding mechanisms 44, 58 in the mutually orthogonal biaxial directions.