To provide a polishing method and a polishing device capable of extremely smoothly polishing without leaving a sub surface damage on surfaces to be polished to form the surfaces to be polished free from chipping, and accurately polishing even a curved surface.

An object to be polished (diamond cutting tool 20) is held by a cutting tool holding mechanism having adjustable angle and swing. The flank 20a and the face 20b of the diamond cutting tool 20 are polished by a plate-like polishing surface plate 10 having a deformable polishing surface. The polishing surface plate 10 is formed of a circular quartz plate having a thickness of 1 mm or shorter and a diameter of 20-40 mm. The surfaces to be polished (the flank 20a and the face 20b) are radiated with an ultraviolet L from an ultraviolet light source lamp 11. The rotational speed, position, and swing angle of the polishing surface plate 10 are adjusted by an automatic spindle swing mechanism.