To establich a method to dress an inner peripheral blade in a wafer cutting device and capable of dressing without requiring a special holding mechanism to carry out dressing and accordingly without suspending wafer cutting.

A reinforced part 2 of thermosetting resin provided on an outer peripheral edge of a wafer 1 is formed by crushing a grindstone formed by baking a resin or glassy binder by abrasive grains of the number selected from grain sizes #320-#800 in less than 0.8 mm in the maximum diameter and mixing 4%-20% of it in volume, and an inner peripheral blade is devised to be dressed for each cutting by cutting the formed reinforced part with cutting of the wafer 1.