PURPOSE: To prevent adherence of a burr and warp of a web from being generated, by cutting a shape steel being placed so that the axial line of its flange or web forms an angle except a parallel and a vertical angle with respect to a cut surface when the shape steel having the flange and the web is sawn.

CONSTITUTION: A rotary saw blade 3 appears crossing at a right angle with the lengthwise direction of a shape steel to be sawn, placed on a table and having a flange and a web, and when the shape steel is sawn, the method enables the shape steel to be sawn with no adherence of a burr in such a manner that a cut angle, formed by the axial line of a flange or web cross section and the tangent of the rotary saw blade 3 in a sawn part on said axial line, can be changed. That is, if the shape steel 2 to be sawn stops in the sawn position, the method, transversely moving a transfer guide 4b in the direction to a fixed guide 4a, presses the bottom end of a lifting piece 6 by a pressing jig 7. The method, lifting one end of the shape steel 2 to be sawn by said lifting piece 6 and fixing the shape steel 2 to a predetermined height (x) through the roller table 1, lifting piece 6, fixed guide 4a and a floating preventing metal fixture 8, cuts the shape steel.