a semiconductor device has a semiconductor substrate , a first insulating film disposed on the semiconductor substrate , and groups of resistors made of polycrystalline silicon and disposed on the first insulating film . at least some of the groups of resistors include at least one dummy resistor made of polycrystalline silicon . a second insulating film is disposed on the resistors and on the at least one dummy resistor of the resistor groups . first metal portions are disposed in respective contact holes disposed in the second insulating film for connecting respective portions of the resistors in the respective resistor groups . second metal portions are disposed on the second insulating film and over the resistors and the at least one dummy resistor in the respective resistor groups .