A surface height of a protective tape joined to a wafer mounted and held on a separation table is detected, an operation amount of approaching a joining member to the protective tape until a separation tape wound around the joining member contacts the protective tape based on detected information, the joining member is operation controlled to approach the protective tape based on the calculated operation amount, the joining member and the separation table are relatively moved along a direction of a surface of the protective tape in a state of maintaining the height of the joining member to join the separation tape to the protective tape, and the separation tape is separated from the surface of the wafer integrally with the protective tape.