PURPOSE: To finish the whole surface into the uniform and smooth state by crushing unevenness formed on the metal surface by crystal structure, acid cleaning, corrosion and other ways not by machining at the time of burnishing by a roller or a ball.

CONSTITUTION: A roller burnishing tool 1 is inserted into a metal pipe 2, in the direction of an arrow mark while being rotated. This roller burnishing tool 1 is provided with plural rollers 3, 4 and a mandrel 5. In this case, unevenness formed on the surface of the metal pipe 2 by crystal structure, acid cleaning, corrosion and other ways not by machining is crushed, or burnishing is performed after making unevenness not by machining grow positively or making it into a complex. That is, the whole surface can be finished into the uniform and smooth state without directionality like electrolytic polishing by utilizing the unevenness, formed on the surface of the metal pipe 2, as the burnished quantity (crushed quantity).