As a method for constituting a pre-metal interlayer insulating film, such method is considered as forming a CVD silicon oxide-based insulating film having good filling properties of a silicon oxide film by ozone TEOS, reflowing the film at high temperatures to planarize it, then stacking a silicon oxide film having good CMP scratch resistance by plasma TEOS, and, further, planarizing it by CMP. However, it was made clear that, in a process for forming a contact hole, crack in the pre-metal interlayer insulating film is exposed in the contact hole, into which barrier metal intrudes to cause short-circuit defects.In the present invention, in the pre-metal process, after forming the ozone TEOS film over an etch stop film, the ozone TEOS film is once etched back so as to expose the etch stop film over a gate structure, and, after that, a plasma TEOS film is formed over the remaining ozone TEOS film, and then the plasma TEOS film is planarized by CMP.