In Birdman, the camera follows Michael Keaton around in one seemingly single take, a performance that has made him an Oscar favourite. He talks about how the film has redefined movie-making, his unpredictable career and how he would like to be hit by a meteor

Michael Keaton is unwell. His assistant is on the phone frantically arranging an appointment with a Notting Hill doctor. It all sounds rather grave, but the actor, who greets me in his hotel room with a fist-bump, followed immediately by an apology for that fist-bump (“A travelling cold. Don’t wanna pass it on”), is some considerable distance from death’s door. He has arrived in London straight from New York, where he delivered a goofy speech at the Gotham awards before collecting the best actor prize for his performance in Alejandro González Iñárritu’s thrilling, kinetic backstage comedy, Birdman. (“I want to thank the fine folks at Gotham,” he told the audience. “It feels good to be back home. Not to toot my horn, but when was the last time you saw the Penguin or the Joker cause any problems?”)

His character in Birdman, an actor making a last-ditch grab for integrity by mounting a Raymond Carver adaptation on Broadway, is haunted by the voice of the superhero he played in a run of 1990s blockbusters. “Shave off that pathetic goatee!” it tells him. “Get some surgery. Sixty’s the new 30, motherfucker!” Keaton has a snarky inner voice too. “We all do,” he says. His tends to get louder on those days when he’s feeling depleted. Days like today.

“Just in from New York. The press, the awards. All really fun. Really fun. Me being grateful, saying: ‘Isn’t this fun?’ Got on the plane, couldn’t sleep. Oh, man. I’m wondering how I’m going to get through today. I’ve just finished another movie, you see?” He’s referring to Spotlight, about the Boston Globe’s coverage of a Catholic sex abuse scandal, in which he stars with Mark Ruffalo. “And the voice back here in my head is going a little crazy. It’s saying: ‘If you’d said no to Spotlight, you could’ve taken a little break. All you had to do was say no and you could be resting right now …’ You recognise you’re getting into that downward spiral. You have to laugh it off or …” His eyes linger somewhere over my left shoulder. “I dunno. You gotta try to turn the voice into your pal. You have to recognise what’s happening: ‘Oh yeah, I’m doing that crazy shit again.’”

Facebook Twitter Pinterest ‘In Birdman, there’s nowhere to hide’ … Michael Keaton. Photograph: Taylor Jewell/Invision/AP

At 63, Keaton looks perky and youthful. He can pull off a dad-at-the-DIY-store ensemble—white weekend trainers, white shirt, the smooth, stiff blue of new denim – without coming across as a fuddy-duddy. His silver hair is cropped close to the scalp and his face is hard and brown as a nut. He looks so spry that I contemplate asking if he has been injecting himself with the semen of baby pigs. But what if he doesn’t twig that this is a reference to Riggan Thomson, his character in Birdman, who is rumoured to have gone to those extreme lengths to preserve his features? Things could turn nasty. Keaton is said to have quite a temper. “I’m a good thrower,” he once admitted. “And a kicker.” Perhaps it’s best that I do what Keaton himself has never done: play it safe.

Birdman has changed his life every bit as much as his firecracker debut in Ron Howard’s 1983 Night Shift, where he played a hyperactive morgue attendant who moonlights as an amateur pimp, or any of his macabre collaborations with Tim Burton. The new film begins with a shot of a meteor blazing towards earth and it is this image that Keaton has used to describe his involvement in the film – sometimes, he says, you have to stand out in the desert and wait for that meteor to hit you. “That’s what I’ve been doing for the last couple of years. Looking. Making a few manoeuvres. Some adjustments. Just trying to get in the way of something.” I point out that his chosen metaphor also contains a destructive, even deadly, component. Meteors tend not to leave their targets unscathed.

“That’s very true,” he laughs. “I guess I just saw it as this kinda ‘Boom!’ and lights going off and me standing there glowing. But you’re right. I could have been shattered to fucking dust. Well, Birdman is a very risky movie. I knew I wanted to do it just from watching Alejandro’s other work. I told a friend: ‘I would have done it based on Amores Perros alone.’ And he said, ‘I would have done it based on the car crash in Amores Perros alone.’ But as an actor, you’d be a lot safer in his other movies with all their different stories. In this one, there’s nowhere to hide.”

Facebook Twitter Pinterest Keaton in Beetlejuice. Photograph: Sportsphoto Ltd./Allstar

He is referring not only to the emphasis on him – he is in almost every shot, the camera as close to him as his own perspiration – but to the illusion, audaciously sustained, that the picture has been filmed in one two-hour take. Would it have changed the tenor of his performance if that hadn’t been the case? “Yes, I don’t think we could have made it without that. There was a part where Zach Galifianakis and I were saying: ‘Why don’t we make the movie the normal way? Why are we doing it like this?’ Then you see it and … woah. At about minute four or 11, you feel that door behind you slowly click shut and you go: ‘OK, now I’m in. There’s no getting off.’ It might be extreme to say this, but other people have said it too so I’m gonna go ahead.” He gathers himself. “Birdman has kinda … changed things.” He glances at me for a reaction. “I’m not saying you won’t see traditionally made movies any more. But I’ve had meetings with directors and they’ve said it makes them rethink everything. You can hate this movie but you have to talk about it. It’s going to go down as one of the most interesting movies ever made.”

Whatever history decides, it is certain that Keaton’s career has been revived and transformed. He finds himself in a markedly different situation today from the one he was in when I met him five years ago. After 25 years as an actor, he had just directed his first feature, The Merry Gentleman, in which he brooded silently as a suicidal assassin. That movie is now more or less forgotten, except in court, where Keaton is being sued by the production company: it is alleged that, among other derelictions of duty, he abandoned the editing suite to go fly-fishing near his Montana home. There is a real possibility that he could take the stand next March in a federal trial. But that looks like small potatoes compared with the fact that, only a week before, he will in all likelihood be clutching the Academy Award for best actor for Birdman. (Odds currently stand at 4/6.)

Facebook Twitter Pinterest Keaton in Jackie Brown. Photograph: Everett Collection/Rex

The movie exploits deliciously the frisson between performer and role. (In one scene, he is even shown demolishing his dressing room in a tantrum – he’s a good smasher-upper.) Thomson bailed on the Birdman series in 1992, the same year Keaton bowed out of the superhero genre with Batman Returns. Birdman is Thomson’s albatross but it would be a mistake to say that Batman was an equivalent burden. By the time he donned the cape in 1989, to the horror of comic-book fans who bombarded Warner Bros with letters of complaint, he also had the putrefied prankster Beetlejuice to his name. (That was his first collaboration with Burton: the director recently expressed a desire to make a sequel but Keaton tells me he’s heard nothing: “I’ve been talking about wanting to do it for years but no one ever did anything about it.”) The integrity he brought to Batman eclipsed anything the character gave to him, with the exception perhaps of temporary commercial clout.

“The first Batman was a risk for everybody,” he says. “Tim didn’t just change that whole genre – he made it. That could really have gone south. And I happened to be his guy.” What separates Thomson from Keaton, I suggest, is that the former probably never had a role as demented as Beetlejuice. Nor would he have played a yuppie-taunting psychopath, as Keaton did in Pacific Heights, immediately after his superhero payday. “That’s a very good way of putting it. I wish I’d thought of that. He probably did a Speechless, right? [the 1994 comedy in which Keaton and Geena Davis played rival political speechwriters]. And he was a good actor. If he had only been bad he would never have got to be Birdman. Pick any of those movies – the Avengers, anything, they’re not bad actors. The Dark Knight – Christian Bale is a fucking monster! He’s unbelievable. He’s awesome. Riggan’s mistake was to let it define him.”

That’s something that never happened to Keaton. Audiences will have their favourite roles. It might be the manic stay-at-home father in Mr Mom or his double-whammy playing the same smarmy FBI agent in two Elmore Leonard adaptations (Out of Sight and Jackie Brown). More recently he was a hoot as Captain Gene, obliviously quoting TLC in The Other Guys (“Don’t go chasing waterfalls …”), and as the voice of the dandyish, overexcitable Ken doll in Toy Story 3. But whatever Keaton has done, he has always had an enviable ability to change tack before it grew stale. When he began to tire of the initial early-1980s persona that he carried over from standup into his early movies – what he calls the “glib young guy” – he snuffed it out. He was through with Batman after two stabs.

Facebook Twitter Pinterest Keaton with Emma Stone in Birdman. Photograph: Allstar/Fox

“I suppose I’m patting myself on the back here,” he says. “But you’ve got to have a sizable pair of balls to be that way. Financially I could’ve done a whole lot better – and, by the way, I’m doing just fine. But that’s the short game. Maybe I could’ve gone on doing the same stuff and people wouldn’t have got bored but you know what? I would have got bored.” Avoidance of boredom may be the closest thing Keaton has to an outright strategy. He is fluent in the politics of Hollywood (“You’ve got to drop in a studio picture here and there”) and diplomatic enough to be wide-eyed about the Oscar race (“It’s amazing to see it all unfolding around me!”) immediately after assuring me: “All actors are my brothers and my sisters. It ain’t cool to compare or disparage them. It ain’t polite.”

It all comes down to staving off boredom. “I’m just shocked and thankful that I’ve gotten away with everything – experimenting here, trying at this, failing at that, being good in some things, not so good in others. It’s kind of amazing that people are still sticking by me. When they come up to me in the street, I just want to write them all cheques.” He mimes doing so. And it’s a sweet idea. But possibly he wants it only in the same way that he “wants” to get hit by meteors.

Birdman is released in the UK in selected cinemas 26 December and nationwide 1 January.