A method of manufacturing a semiconductor device includes assigning a plurality of chip regions on an epitaxial-growth layer of a semiconductor substrate where the epitaxial-growth layer is grown on a bulk layer and forming a plurality of device structures on the plurality of chip regions, respectively, thinning the semiconductor substrate from a bottom-surface side of the bulk layer, bonding a supporting-substrate on a bottom surface of the thinned semiconductor substrate, selectively removing the supporting-substrate so that the bottom surface of the semiconductor substrate is exposed, at locations corresponding to positions of each of main current paths in the plurality of device structures, respectively, dicing the semiconductor substrate together with the supporting-substrate along dicing lanes between the plurality of the chip regions so as to form a plurality of chips.