After etching the interlayer dielectric film 4 formed on the lower layer interconnect line 1 into a shape with holes, the upper layer dielectric film 6 is etched into a shape with trenches utilizing the etching stopper 5. The etching stopper 5 which is exposed at the bottom of the trench is removed by additional etching, and then, the interlayer dielectric film 4 which is exposed at the bottom of the trench is etched back to a predetermined thickness. Subsequently, the hole and the trench are filled with an interconnect metal 10.