To dress a grinding wheel be in a highly accurate contour shape even if heat displacement occurs and to improve the work efficiency of dressing and the service life of the grinding wheel by reducing a cutting amount.

A boss 5 is provided in the side end surface of a dresser 1, abrasive grains 6 are adhered to a side end surface opposite the boss 5 of a grinding wheel 2, and an AE sensor 3 is disposed in the grinding wheel base main body 14 side of the grinding wheel 2. A detecting signal is transmitted from the AE sensor 3 to a control part 4 by contact between the boss 5 and the abrasive grains 6. During re-dressing after grinding, the boss 5 is contacted with the abrasive grains 6, X and Y coordinate is calculated at this time and a difference between this coordinate and a previous X and Y coordinate. By performing original point position correction equivalent to this difference, dressing is performed as in the case of no heat displacement.