It is an object of the present invention to provide a manufacturing method of semiconductor device whereby the number of processes is decreased due to simultaneously forming a contact hole in a lamination film of different material and film thickness (inorganic insulating film and organic resin film by conducting etching once. By setting the selective ratio of dry etching (etching rate of organic resin film 503/etching rate of inorganic insulating film 502 containing nitrogen) from 1.6 to 2.9, preferably 1.9, the shape and the size of the contact holes to be formed even in a film of different material and film thickness can be nearly the same in both of the contact holes.