A wafer formed thin through a back grinding process is placed on a support table included in an alignment stage. When a faulty suction is caused by a warp of the wafer, a surface of wafer is pressed by a pressing plate to be corrected and held by suction. The wafer held by suction is transported, along with the alignment stage, to a mount frame preparing unit at the next step. The wafer is received while being held by suction by a chuck table contacting the surface of wafer.