Abstract: On a back face of a silicon wafer before dicing, tapered grooves having sloped side walls are formed by anisotropic etching along with thin portions. Strain gauges are formed on each thin portion, thereby forming a sensor chip on the silicon wafer. The back face of the silicon wafer is attached to a self-adhesive seat. Thereafter, the silicon wafer is cut along the grooves by a dicing blade to divide it into each sensor chip. In dicing, the side faces of the dicing blade cut the sloped side walls of the tapered grooves. As a result, the silicon wafer is diced into individual sensor chip having no cracks and chippings.