PURPOSE: To equally flow out a iiquid to each part of an abrasive grain layer and to eliminate the clogging accompanied by the progress of lapping by integrally joining a mesh like sheet with an abrasive grain layer part faced to the surface to the one side end face of the porous body of the continuous hole system fitted to a holder end face.

CONSTITUTION: The liquid fed from the liquid feeding port 7 of a holder 1 is passed through the porous body 2 of a continuous hole system at lapping time. In this case, the liquid is uniformly flowed at each part because the distribution of the holes of this porous body 2 is uniform at each part. The liquid of each part is then fed directly especially uniformly to the gap of each abrasive grain 11 of an abrasive grain layer 12. As a result, the liquid is quickly fed to each part and no clogging of the gap of each abrasive grain 11 accompanied by the progress of lapping is caused.