Today, as he turns 70, Michael Caine can look back on a career encompassing 85 films and two Oscars. He discusses his career -and the critics - with Sharon Waxman.

His face is smooth and pink, with just a hint of jowls; the eyes a deep, stormy blue; the drooping lids more pronounced now, especially on the left. Michael Caine - sorry, Sir Michael Caine - is kicking back in Beverly Hills with the ease of a man who has been part of the scenery for a very long time.

In the next room is his wife, the stunning Shakira Caine, a Guyanese-born beauty queen. By his side, childhood friend and press agent Jerry Pam. The shoes are off, the blue-stockinged feet propped up on a coffee table in composer Leslie Bricusse's art-laden family room - Caine's home away from home.

The day's Wall Street Journal is laid out on the coffee table, open to a reverential analysis by critic Joe Morgenstern of Caine's starring turn in The Quiet American, a post-colonial drama set in Vietnam. The actor has practically committed it to memory.

"Read the last line," he says in a voice both silken and unimpeachable. "Over the years and the decades, Michael Caine has given one peerless performance after another with so little fuss, let alone flash" - Caine leans forward for this last part and joins in - "that it has hardly looked like acting at all." All those decades, all those movies (85 by his count, more if you include television), all those Oscar nominations (including two wins), all that money, that fame, that privilege add up to a handful of words in tomorrow's fish-wrap that finally, as he sees it, got it right.

"It's my favourite review ever," he says, his Cockney lilt softened by years of paddling in the Hollywood pond. "I don't normally read my good reviews, but someone has finally got it. He said exactly what I'm trying to do."

What is he trying to do, exactly? At an age when pals such as Roger Moore have set off for sunny retirement, Caine has been busy biting into one chewy role after another, from Little Voice in 1998 and The Cider House Rules in 1999 to Quills in 2000 and, last year, The Quiet American. Caine has been winning not only accolades and awards but also a sort of artistic freedom that comes, perhaps, with practice, practice and more practice.

"Movie acting is about covering the machinery," he says. "Stage acting is about exposing the machinery. In cinema, you should think the actor is playing himself, if he's that good. It looks very easy. It should."

But it's not, he assures.

"To disappear your complete self into a character is quite difficult," he says. "I've tried it 85 times, and I've succeeded two or three times."

Caine has always hovered somewhere between actor and star. He came to prominence in his native England, where acting has traditionally involved a posh accent and a matching attitude. Instead, he had a two-bit accent and an attitude more rough than toff, which only made him more determined. He honed his craft on stage before launching himself into film, then left to chase the fame of a Hollywood leading man, but it never came, so back he went.

He's taken good roles in lousy movies and lousy roles in lousy movies, but often enough Caine has been indelible in films that became instant classics - Alfie and The Man Who Would Be King, to name just two.

He has appeared in some decent little films (Get Carter, 1971) and some godawful big films (Get Carter, 2000).

Sometimes he did it just for the money, and said so. He famously remarked that he never saw the stink bomb that was Jaws: The Revenge, but he saw the house it bought (his mansion in Oxfordshire), and it's terrific.

Now, in the age of the celebrity, Caine seems to have come full circle. He begins his 70s with his abilities more honed, more subtle than ever. His screen work is unfailingly interesting, even when it's in Austin Powers In Goldmember. At the same time, he cherishes his precious comforts: his wife, his two grown daughters, his gardens back home in England.

"I've now got the chance to do what I want," he says. "I don't work for economic reasons, though I do get paid. I work because I want to. It has to be a script I really want to do." One of those scripts was certainly The Quiet American, a small film based on a 1955 novel from the roving pen of British writer Graham Greene. Directed by Phillip Noyce, Caine starred as Thomas Fowler, a jaded, opium-inhaling correspondent based in Saigon for a British newspaper, observing the end of the French colonial experience and the incipient US one.

The US experience arrived in the form of young, handsome Alden Pyle, played by Brendan Fraser, an aid worker involved in the delicate (and not so delicate) political manoeuvrings of the time.

When Pyle fell in love with Fowler's young concubine Phuong (played by Do Thi Hai Yen), the entanglement was played out against the backdrop of a land where few things are what they seem.

The film was praised for its languorous aura and its subtle weave of drama, politics and sex. Caine loved everything about the film - the script, the shoot, the result. "I regard the film as extraordinary because it has an incredible sense of time and place," he says. "That doesn't exist, and Phillip Noyce put it there."

Caine had a lot to go on in creating Thomas Fowler. He had served in the British army in Korea as a young man, and he'd met Graham Greene, whom Fowler resembles. (Caine once encountered Greene in a London restaurant after having appeared in The Honorary Consul, a film based on another of the author's novels. "He told me he thought it was a load of crap," Caine recalls. "But we became friendly because he liked my performance.")

Caine knew a bit of South-East Asia, and the film was shot in Vietnam. "I was away from my own environment, surrounded by Thomas Fowler's world. I'd see dozens of Fowlers with their concubines walking around - middle-class Englishmen disgruntled at England. I was steeped in it . . . It was Graham Greene land, it really was."

Whatever the reasons, Caine's delivery seemed to conquer any last reticence critics may have had about him. "Caine gives the kind of seemingly effortless performance it needs an entire career to prepare for," wrote Kenneth Turan of the Los Angeles Times. "Caine's Fowler, open to tears, to rage, to disappointment as well as love, seems actually to have the character's life."

"Fowler may be the richest character of Mr Caine's screen career," Stephen Holden wrote in the New York Times. "Slipping into his skin with an effortless grace, this great English actor gives a performance of astonishing understatement."

These notices please Caine no end, and he makes no attempt to disguise it. If anything, he's happy to elaborate. "I become," he says, when asked about his craft. "I have my own principle, which is to hide the work. You should think, 'I wonder what's going to happen to Thomas Fowler?' not, 'Isn't Michael Caine doing a great job?'

"It's always a gamble. It's a high-wire act, and if you fall off you die. If I feel a performance is going pear-shaped, I'll muck about with it. But I never mucked about with Thomas Fowler. I was just him.

"I do nothing with Fowler except be him. You can like him, dislike him, you can find him funny, unfunny, stupid, not stupid. He's just there. And you can make up your own mind."

He's already gone on to other projects. Caine co-starred in what he calls "a mad Irish comedy, The Actors, written and directed by Conor McPherson about a theatrical group putting on Richard III, filmed in Ireland and also starring Dylan Moran. Caine plays a roaring bad version of Richard, the closest he'll apparently ever get to the Royal Shakespeare Company.

He's equally proud of an upcoming turn as a Texan in Secondhand Lions, with Robert Duvall, a comedy about a young boy (Haley Joel Osment) forced to spend the summer with his eccentric great-uncles (Duvall and Caine), cowboys with mysterious and dangerous pasts. Caine studied the local twang with a dialogue coach but spoke in Texan only when delivering his character's lines, and he refuses to demonstrate now. This, however, leads to a digression about Caine's friendship with John Wayne. Caine stands and stumbles sideways across the room, the Cockney doing the John Wayne walk.

Nevertheless, Caine doesn't just spend his time memorising his good reviews. He memorises the bad ones, too.

The first review he recalls reading was of his performance in Alfie, which most critics loved. Caine remembers a review saying the film was "destroyed by the central performance of Michael Caine".

The other day he got another bad review in a British newspaper (back home they love to knock him around), marking the release of "yet another film proving Michael Caine can't act", he said.

Why does he bother reading these, much less memorising them? He chuckles. "I read 'em because I think it's silly," he says.

"It makes the critic look a fool. You get those kinds of reviews of people like me because they don't know what they're talking about, and they've got to impress an editor."

A pause, a sniff and a wry smile. "You know, to say Michael Caine can't act is a bit silly."

The Actors is due to be released later in the year.