In a method for allowing a cutter blade to relatively travel along an
outer periphery of a semiconductor wafer to cut a protective tape joined
to a surface of the semiconductor wafer in conformity with an outer shape
of the semiconductor wafer, the cutter blade is allowed to relatively
travel along the outer periphery of the semiconductor wafer with a
positioning notch provided on the outer periphery thereof. The cutter
blade is rotationally turned at the fore half of the notch recessed on
the outer periphery of the semiconductor wafer during the relative travel
of the cutter blade in such a manner that its blade tip is directed
toward the center of the wafer. In contrast, the cutter blade is
rotationally turned at the rear half of the notch in such a manner that
its blade tip is directed toward the outer periphery of the semiconductor
wafer.