A method of manufacturing a semiconductor device able to reduce the number of manufacturing steps and attain the rationalization of a manufacturing line is disclosed. The semiconductor device is a high-frequency module assembled by mounting chip parts (22) and semiconductor pellets (21) onto each of wiring substrates (2) formed on a matrix substrate (27) after inspection. A defect mark (2e) is affixed to a wiring substrate (2) as a block judged to be defective in the inspection of the matrix substrate (27), then in a series of subsequent assembling steps the defect mark (e) is recognized and the assembling work for the wiring substrate (2) with the defect mark (2e) thereon is omitted to attain the rationalization of a manufacturing line.