To provide the formation method of an interlayer insulation film, especially for shortening chemical mechanical polishing process time in the manufacturing method of a semiconductor element.

This formation method for the interlayer insulation film of the semiconductor element is provided with the stage of forming a first insulation film 50 on a semiconductor substrate provided with an element such as a transistor in the inside, the stage of forming many metal wirings 60 made of the laminated structure of a Ti/TiN film 52, an Al film 54 and a TiN film 56 on the first insulation film, the stage of forming a spacer 70a made of the TiN film on the side face of the metal wirings, a stage of forming many metal wirings provided with the spacer and a second insulation film 72 formed of an insulation material, whose vapor deposition speed is made different by the material of a lower film on the first insulation film, the stage of forming a third insulation film 74 on the second insulation film and the stage of polishing the third insulation film by a CMP(chemical-mechanical polishing) process.