To grind chemical machinery at stabilized abrasive quantity with the abrasive quantity of a substrate sufficiently controlled.

This device 30 is equipped with: a grinding pad, a grinding table being rotating while holding the pad, a substrate holder for holding a substrate to rotate a film on the substrate while pressing the film onto the pad, a dresser for resetting the pad, and a conditioning controller 34 having a grinding rate calculating part 44 for calculating a grinding rate, and a resetting condition setting part 46 for setting the resetting condition of the pad based on a calculated grinding rate. Consequently the pad can be reset by a suitable condition through a dresser at every chemical machinery grinding to the setting number of the substrate, allowing grinding at stable abrasive quantity with the abrasive quantity of the substrate sufficiently controlled.