A semiconductor wafer processing method for planarizing an additional layer formed on the front side of a semiconductor wafer. First, the wafer is held on a chuck table included in a cutting device in the condition where the additional layer is exposed, and a table base supporting the chuck table is moved toward a working position. In concert with the movement of the table base, the exposed surface of the additional layer is cut by a bit of a cutting tool rotationally driven by a spindle motor. Thereafter, the exposed surface of the additional layer is polished by a polishing device to planarize the exposed surface of the additional layer.