"The Devil Wears Prada," a movie starring Meryl Streep in one of her most wickedly inspired comic performances, casts a knowing eye on the international couture business through the lens of its U.S. bible, Vogue magazine, and that publication's famously feared editor, Anna Wintour. Or ... no, that's not exactly right. Actually, the magazine is called Runway, and its editor, played by Streep, is named Miranda Priestly. This is because those are the names employed by author Lauren Weisberger in the bestselling 2003 novel on which the movie is based. Weisberger has been coyly insistent about denying that her book is modeled on Vogue or Wintour. But since she spent nearly a year working at Vogue as an assistant to Wintour, that assertion has generally been dismissed, especially in Fashionville, with a lip-licking smirk.

As in the book, the story concerns a young woman named Andy Sachs (Anne Hathaway), a freshly minted college graduate who's moved to Manhattan to pursue a career as a journalist. The job market is ferociously competitive, as always, and she winds up at the editorial offices of Runway — an alternative universe peopled by impossibly willowy women clacking around the halls in gleaming designer high heels — to interview for a slave-level assistant position. This is a terrible idea: Andy knows nothing about fashion, has never read the magazine, and therefore has never heard of Miranda Priestly. She somehow gets hired, though, and soon learns.

Miranda's arrival at the office every morning is an occasion for gut-tightening panic among her employees. Tossing back her sleek, silver-gray hair as she exits the elevator, she sails through the door emitting an unending sigh of refined disappointment at everything and everyone in her orbit, lobbing little grenades of demand and desire at every staffer she passes: "Get me Isaac." "Where's that piece of paper I had in my hand yesterday?" "Get me that little table I like in that store on Madison." Requests for clarification are icily swatted away: "Please bore someone else with your questions."

Andy is completely at sea. Although any character played by Anne Hathaway must unavoidably be pretty in a fairly unimprovable way, around the Runway offices, Andy's a dog. For one thing, she's still wearing her sensible little skirts and sweaters from college; and she clearly hasn't yet made the leap to $200 haircuts. Her fellow workers are openly contemptuous. "Who is that sad little person?" asks Nigel (Stanley Tucci), the magazine's effete photo chief. "Are we doing a before-and-after piece I don't know about?" Andy's immediate superior, an intensely snooty English girl named Emily (Emily Blunt), is afraid that Andy's lack of fabulousness will somehow reflect badly on her — and possibly result in Miranda not taking her along to the big spring fashion shows in Paris. "If you lose Paris for me," she hisses, "I will search every Blimpie's in the tri-state area till I find you."

Andy never had a "weight problem" until she arrived at Runway, land of the stick-like glamazons. Nigel, taking pity, counsels her in terms of dress sizes. "Two is the new four," he says. "Zero is the new two." Andy tells him she's actually a size six. "Six," he says, "is the new fourteen." But he decides to come to her rescue, pulling together fabulous new outfits for her from the office wardrobe closet. Before long she's a full-fledged fashionista, resplendent in loan-out Chanel and Manolos and looking very little like the serious journalist she previously wanted to be. The boyfriend she lives with, Nate (Adrian Grenier), a chef in a downtown restaurant, can feel her slipping away from him. And indeed, when a slick, smarmy magazine writer named Christian (Simon Baker) starts hitting on her, Andy does feel the unaccustomed stirring of erotic temptation.

The movie captures New York in all of its media-lashed uproar, from the teeming streets and shops of SoHo to the money-thickets of Tribeca and the chic eateries of the Meat Packing District. And Paris in the spring, with its rain-slicked side streets and twinkling tree lights, has rarely looked so heart-swellingly gorgeous. But the most impressive natural wonder in the film is Streep's Miranda Priestly. She's a woman of bottomless self-absorption — the world at large is her backdrop, but otherwise not her concern. And she manages to impose her monumental ego on her frazzled underlings around the clock, even when she's out of town. (Calling in to the office from some faraway airport, she fumes about the fact that her flight has been canceled. "Some absurd weather problem," she says, as a hurricane batters the departure-lounge windows. "Call Donatella — get her jet.")

It would be easy to trash this abrasive character, but the director, David Frankel, a "Sex and the City" veteran, and the screenwriter, Aline Brosh McKenna, are too classy to take that tack. And in one scene, during a "Runway" staff meeting, they allow Miranda to state her own case, explaining to a skeptical Andy the actual utility of high fashion: how this season's unaffordable designer styles will be knocked off into next season's high-end retail offerings, and will then blossom democratically the following season in shopping malls across the country. "In fact," she says, taking in Andy's humble collegiate cardigan, "you're wearing a sweater that was selected for you by the people in this room."

Meryl Streep has been nominated for 13 Academy Awards over the course of her extraordinary career (she won twice, for "Kramer vs. Kramer" and "Sophie's Choice"), and she'll certainly get another Academy nod for her performance in this picture. Like Judi Dench and Maggie Smith in Britain, she's a national theatrical treasure, and there are few more pleasurable movie-going events than the arrival of another film in which she so delectably demonstrates why.