WASHINGTON — Rep. Howard Berman keeps a big Thermos behind his desk. That way, he never has to ask anyone to fetch coffee for him.

The new House Foreign Affairs Committee chairman also picks up his own dry cleaning and drives his own car. It is a self-sufficiency that Mr. Berman has carefully nurtured over his 13 terms in Congress. Now that he has ascended to one of the most influential posts on Capitol Hill, succeeding the late Chairman Tom Lantos, he still rejects the trappings of power, and prefers to keep operating as a behind-the-scenes player.

He even barred an Associated Press photographer from taking his picture for this story.

“Sometimes the best things are done when the media doesn’t know about it, because then a lot of other people don’t know about it,” Mr. Berman said. “The media is a conduit of information to the people who wouldn’t like what I was doing.”

It’s not that Mr. Berman has anything to hide, friends say.

“He’s much more interested in accomplishing things than being out front and visible,” said Rep. Henry Waxman, a Democrat of California, who’s known Mr. Berman since their college days at the University of California, Los Angeles. They presided over a famously effective Democratic machine in Southern California in the 1970s and ’80s that helped elect like-minded politicians to local and state offices.

Mr. Berman’s committee has oversight over policies in Iraq, Afghanistan, and the rest of the globe’s hotspots. He’s been in Israel and Iraq over the weekend with the House speaker, Nancy Pelosi, on his first overseas trip as chairman. Outside of Washington he has had his fair share of political scrapes. In 1980, the Democrat made a grab for the speakership of the California Assembly but was outfoxed by Willie Brown, who went on to become California’s longest-serving Assembly speaker and mayor of San Francisco. In 2001, he drew ire when his congressional district was redrawn in a way seen by some Latinos as diluting Hispanic voting power. Mr. Berman was able to emerge from the episode with strong Latino support due to his long record as a champion of farmworker and immigrant rights.

In Washington, he’s thrived on an understated approach. His leadership style is different from that of Lantos. Lantos, also a Democrat, was the only survivor of the Holocaust to serve in Congress and his dignified bearing and eloquent oratory made him one of the institution’s most recognizable figures.

Mr. Berman, by comparison, is unprepossessing, although like Lantos he represents a district in California. Mr. Berman’s graying, curly hair is rumpled. His speaking style is halting and thoughtful. He doesn’t have a press secretary.

A photo in Mr. Berman’s office attests to the fact that he visited a grand cathedral in St. Petersburg, Russia — wearing a Hawaiian print shirt.

“He combined a real passion with a tremendous eloquence,” Mr. Berman said of Lantos. “That’s just not my strong suit. I’m more of an inside animal.”