Abstract: An underlying interconnection is formed on a semiconductor substrate, and an interlayer insulating film is formed on the semiconductor substrate and the underlying interconnection. A metal film is deposited on the interlayer insulating film, and is patterned in an interconnection pattern, and a first opening for connecting the metal film to the underlying interconnection is patterned, thereby forming an overlying interconnection. Then, a protection film is formed so as to cover the surfaces of the overlying interconnection and the interlayer insulating film. Next, a photoresist film is formed on the protection film, and is patterned to provide a second opening larger than the first opening in the protection film above the first opening and provide a third opening in a pad-portion forming region on the overlying interconnection. At the same time, with the overlying interconnection as a mask, the interlayer insulating film is selectively etched out to form a through hole.