PURPOSE: To precisely and efficiently perform polishing work of the surface of a work even if it is having a complicated cross sectional shape.

CONSTITUTION: In the sanding method, a sanding belt V, being pushed by a pressure pad 21, is slidingly contacted with a work W retained at a fixed position over a total length of the work W to polish a surface of the work W, the work W turns around the traveling direction of the sanding belt V as its turning axis, and a copying model M perform in the same movement as the work W is juxtaposed. A belt guiding sensor 24 abutting on this colying model M for detecting the surface shape thereof is provided, and the pressure pad 21 is made to perform the same movement in accordance with the position of this belt guiding sensor 24.