A method of manufacturing semiconductor device in the method of manufacturing wafer level semiconductor device that can search the defective products from the marking information even when sealing resin is formed on the wafer and a semiconductor device manufactured with the same method. A method of manufacturing wafer level semiconductor comprises a process to seal with a resin material the surface of wafer having the front surface and rear surface and forming a plurality of semiconductor chips on the front surface, a first marking process for marking the position information corresponding to each chip to the region of each chip at the rear surface of the wafer, a process for performing the electrical test to each chip, a second marking process for marking the result of the electrical test to the region of each chip at the rear surface of the wafer and a dicing process for dicing the wafer to each chip.