The scores were 6-3, 6-3.
Henman was hurt by six double faults, including three in the sixth game of the first set that led to Federer's first service break.
Federer, the top seed, bagged his 77th match win of the year and is five wins away from topping his personal-best record of 81 wins.
He won 11 titles a year in 2005 and 2004 and needs one more victory this year to reach double figures for a third straight year.
"I'm very happy with the way I played," Federer said. "He was tough today because I had to come up with passing shots at the right time. Those double faults cost him the match."
After his sixth consecutive win against the 10th-seeded Henman, Federer is 48-2 on hard courts this year.