The invention provides a manufacturing method of an insulating film having a plurality of pores, as well as a manufacturing method of a highly integrated semiconductor device with high yield. According to the invention, a porous insulating film is formed by forming a plurality of pores in an interlayer insulating film using a laser beam, which results in lower dielectric constant of the interlayer insulating film. In addition, a composition containing conductive particles is discharged onto the porous insulating film by a droplet discharge method typified by an ink jet printing method, and then baked to form a wire. As the laser beam, an ultrashort pulse laser beam is preferably used.