PURPOSE: To concentrically supply a sufficient amount of grinding fluid to a grinding surface of a grinding wheel by providing a through hole in a position separated in a circumferential direction reverse to the direction of rotation of an annular holder and in the center direction thereof from an internal peripheral end side of the grinding surface of the grinding wheel mounted on the annular holder.

CONSTITUTION: A grinding wheel holder for a surface grinder is constituted of an annular holder 1 for mounting a grinding wheel T on the peripheral side and a water flow adjusting plate 2 provided in one end surface of the annular holder 1 to provide a through hole 2a in the external edge. This through hole 2a is provided in a position separated in a circumferential direction reverse to a rotating direction 11 of the annular holder 1 and in a direction of the center 0 thereof from internal peripheral end sides of grinding surfaces 4S, 4S' of a grinding wheel mounted on the annular holder 1. In this way, a sufficient amount of grinding fluid can be concentrically supplied to the grinding surface of the grinding wheel.