The Scot was appointed as the successor to the retired Sir Alex Ferguson towards the end of the previous campaign, having spent 11 years in charge of Everton.
While Beckham feels that Moyes will find it difficult at first with the Red Devils, he believes that United can retain their Premier League crown.
"I'm sure he has had lot of mentoring, he is one of those managers that has always picked up the phone and spoken to Sir Alex," Beckham told Sky Sports News.
"It was always going to be difficult job for whoever succeeded Sir Alex because of what the manager has brought to Manchester United, what he has brought to the game.
"But the same players are there and I'm sure a few more will be added over the next few weeks. Being manager of Manchester United is a great job."
Moyes's first Premier League match in charge of United will be at Swansea City on August 17.