An aligned workpiece is mounted on and held by a holding table, and a support board separating mechanism separates a support board from a semiconductor wafer. Herein, a double-faced adhesive tape is left on one of the support board and the semiconductor wafer. Either the support board or the semiconductor wafer on which the double-faced adhesive tape is left is transported to an adhesive tape peeling mechanism while being held by the holding table, and the double-faced adhesive tape is peeled off and removed from the surface of thereof. The separated semiconductor wafer and support board are collected independently.