PURPOSE: To provide grinding with higher accuracy by a method wherein a pair of grind stone wheels, by moving an X table, is allowed to be eccentric so that they overlap each other in such a condition that their annular working surfaces have been deviated from each other.

CONSTITUTION: A pair of spindles 7, 8 are noncoaxially located by moving an X table to the right. The eccentricities of both spindles are determined by the axes of their working surfaces, and their annular working surfaces are made to overlap each other while the surfaces have been deviated from each other when looking both wheels 13, 14 in an axial direction. Furthermore, feeding motion in a Y direction is continued until there occurs a strike on the part of the whole working surfaces 15, 16 of the grind stone wheels 13, 14 by making the working surfaces plane off each other. Thus the truing by placing the working surfaces 15, 16 in an eccentric condition and making them press against, and plane off each other enables grinding with higher accuracy while preventing undulation.