A method of manufacturing a semiconductor device comprising: first, forming ineffective chips in a circumference of a first main surface of a semiconductor wafer; and forming effective chips in a region surrounded by the ineffective chips; then, providing an insulating film on dicing lines which partition the effective chips and the ineffective chips; after that, forming a front electrode on the effective chips and the ineffective chips; then, forming a layer of polyimide (25, 26) covering the entire upper surface of the wafer, wherein a first portion of the polyimide layer is formed on an outer circumferential portion of the first main surface of the semiconductor wafer with a predetermined width from an outer circumferential end of the semiconductor wafer such that the first portion continuously covers the ineffective chips from the outer circumferential end of the semiconductor wafer to the inside, and a second portion of the polyimide layer is formed inside a region surrounded by the first portion and continuous with the first portion; removing the second portion of the polyimide layer where it covers the front electrode of effective chips and dicing lines covered with the insulating film including a portion of the dicing lines interposed between the ineffective chips, while the layer of polyimide in the first portion in the outer circumferential portion of the wafer remains; forming a metal film on the front electrode formed on the effective chips using plating; forming a rear electrode on a second main surface of the semiconductor wafer; and last, cutting the semiconductor wafer into semiconductor chips along the dicing lines using a blade. first, forming ineffective chips in a circumference of a first main surface of a semiconductor wafer; and forming effective chips in a region surrounded by the ineffective chips; then, providing an insulating film on dicing lines which partition the effective chips and the ineffective chips; after that, forming a front electrode on the effective chips and the ineffective chips; then, forming a layer of polyimide (25, 26) covering the entire upper surface of the wafer, wherein a first portion of the polyimide layer is formed on an outer circumferential portion of the first main surface of the semiconductor wafer with a predetermined width from an outer circumferential end of the semiconductor wafer such that the first portion continuously covers the ineffective chips from the outer circumferential end of the semiconductor wafer to the inside, and a second portion of the polyimide layer is formed inside a region surrounded by the first portion and continuous with the first portion; removing the second portion of the polyimide layer where it covers the front electrode of effective chips and dicing lines covered with the insulating film including a portion of the dicing lines interposed between the ineffective chips, while the layer of polyimide in the first portion in the outer circumferential portion of the wafer remains; forming a metal film on the front electrode formed on the effective chips using plating; forming a rear electrode on a second main surface of the semiconductor wafer; and last, cutting the semiconductor wafer into semiconductor chips along the dicing lines using a blade.