PURPOSE: To connect an upper wiring with a lower wiring through a through hole without being influenced by gas contained in a coated film by covering the boundary or coated film layer, exposed in a through hole formation process, between a lower and upper insulating films.

CONSTITUTION: A lower wiring 2 is formed on a semiconductor substrate 1, and an upper wiring 6, electrically connected with the lower wiring 2 through a through hole 8 formed in an interlayer insulator layer, is formed. On the side wall of the through hole 8, apart from the upper wiring 6, formed is a side-wall coating 7 to cover the boundary between a lower insulating layer 3 and upper insulating layer 5. This prevents gas, contained in coating liquid stagnated in a recess in a coated film layer 4, from spouting from an exposed face in the side wall of the through hole 8 though the air can move through the boundary or coated film layer 4 between the lower insulating layer 3 and upper insulating layer 5. This eliminates a factor which interferes with electrical connection between the lower wiring 2 and upper wiring 6.