PURPOSE: To efficiently decide the movement quantity in the right and left and fore and aft directions, by arranging a scale in the moving direction relative to the grindstone of a table and in the orthogonal direction to the moving direction on the chuck for holding a work or on the table for placing the chuck.

CONSTITUTION: A scale 13 in parallel to the right and left moving directions of a table 2 and a scale 14 in the fore and aft directions orthogonal to the moving directions are arranged on the table 2 along a chuck 4 which holds a work 5. The work 5 is then held on the chuck 4, the length of a grinding face 6 is measured by the scale 13 and the width of the grinding face 6 by the scale 14 respectively. Namely, the range moving a grindstone 11 and the work 5 relatively is decided.