Abstract: A brush-like grindstone (1) has threadlike grinding elements (2) each being a thread that is a collection of long inorganic fibers and is impregnated with resin and solidified. To grind work (W), the grindstone (1) is moved relative to the work (W) with the forward ends of the threadlike grinding elements (2) pressed against the work (W). In order to prevent the grinding elements (2) from breaking, each threadlike grinding element (2) is curved from its base end to its forward end with high hardness of the grinding elements (2) maintained. Also, the grinding elements (2) are formed in an elliptic or oblong cross-sectional shape whose minor axis is aligned with the direction of the curve. Therefore, the grinding elements (2) have extremely high rigidity in the direction perpendicular to the direction of the curve but they easily deform in the direction of the curve.