For several years Meryl Streep has suffered through a succession of roles that were really beneath her (most recently in “Prime” and even “A Prairie Home Companion”), but in this smooth, crisp if lightweight adaptation of Lauren Weisberger’s novel, she finally gets one that’s worthy of her talent. As Miranda Priestly, long-time editor of a style-shaping fashion magazine and, to her young assistant, not only the boss from hell but also the person who almost ruins her life, Streep creates an indelible character and sustains it to the very end. “The Devil Wears Prada” might not be much more that a clever riff on “All About Eve,” but thanks to Streep it’s sharp and witty enough to play on a double bill with that 1950 classic and not completely fold in its presence; it’s probably the best Hollywood working-girl comedy since, well, Mike Nichols’ “Working Girl” (1988).

Anne Hathaway plays Andy Sachs, a recent Northwestern University journalism graduate who applies for a job at New York’s Runway magazine because she can find no “real” news gig. Attractive in a girl-next-door way but hardly the svelte model type and, in her rather dowdy clothes and makeup, no fashion plate, she’s dismissed by Priestly’s prickly, ambitious first assistant Emily (Emily Blunt) but hired by Miranda anyway, who proves about the most demanding, inconsiderate boss imaginable. Nonetheless Andy’s determined to show she can make the grade, and before long she’s been seduced into the Runway lifestyle, responding to Miranda’s beck and call and even buying into the corporate concern with size and clothes–aided by the magazine’s swishy art director and overall arbiter of taste, Nigel (Stanley Tucci)–so much so that the transformation endangers her relationship with boyfriend Nate (Adrian Grenier), a laid-back chef. Perhaps luckily, she finds an alternative in Christian Thompson (Simon Baker), a well-connected writer who takes a shine to her.

The issue, of course, is the old standard one of whether the naive innocent will be permanently sucked into the Dark Side or see the light before it’s too late and save herself. We’ve seen it in all sorts of contexts before, and given today’s fascination with haute couture, it’s understandable that it should be replayed in that rarefied world. Weisberger’s roman a clef, based to a large extent on her own stint at Vogue, is here molded into reasonably clever version of the formula by Aline Brosh McKenna, and the picture has been given an elegant look by production designer Jess Gonchor, art director Tom Warren, costumer Patricia Field and cinematographer Florian Ballhaus; and though David Frankel’s direction isn’t very imaginative, at least it keeps things spry and puts the focus where it belongs.

And that, frankly is on Streep. Hathaway is ingratiating, if a trifle bland, as Andy, and Blunt cuts an amusing figure as a driven, self-absorbed career woman. Tucci, too, does a flamboyant, crowd-pleasing turn as Nigel, and though Grenier and Baker serve mostly as pleasant-looking background, they’re both up to their roles’ modest demands. But it’s Streep who grabs one’s attention from her very first entrance (appropriately preceded by anticipatory hubbub among her staff), and never gives it up; even when she’s absent from the action, she dominates the screen. And she does so without screaming: her Miranda, with perfectly-coiffed hair and strikingly elegant wardrobe, controls all around her not with extravagant displays of temper but soft-spoken commands and contemptuous glances–virtually a regal presence. And yet the film allows her a few moments of humanity to keep Priestly from mere caricature–one fleeting shot with her husband (James Naughton), when Andy intrudes accidentally into their living quarters, a scene during a trip to a fashion show in Paris, when she’s gotten some personally devastating news she must set aside for her job’s sake, and a final shot when she’s allowed the mere hint of an indulgent smile. The brief but telling bits, all played with admirable restraint, are enough for Streep to show us that Miranda isn’t just a monster, but a woman who’s sacrificed virtually everything (and everybody) to get where she is–and stay there.

Aside from Streep, there really isn’t much to “The Devil Wears Prada”–just a fluffy tale of a young woman who ultimately has to chose between becoming her boss or remaining herself. With her, though, it becomes an acting master class in how to make a lot out of very little.