Roethlisberger completed 21-of-29 passes for 275 yards and no interceptions. Cedrick Wilson had five receptions for 92 yards and one score; Hines Ward added 59 yards and a score on five receptions; and Jerome Bettis rushed for 39 yards and one touchdown on 15 carries for the Steelers.
Jake Plummer was 18-for-30 for 223 yards, one touchdown and two interceptions for the Broncos. Ashley Lelie had two catches for 68 yards and one touchdown for Denver, which failed to advance to its first Super Bowl since winning back-to-back titles in 1997 and 1998.
Plummer committed four turnovers which led to 21 Pittsburgh points.
The Steelers, who have not played in the Super Bowl since 1979, will represent the AFC in Super Bowl XL at Detroit on Sunday, Feb. 5.