The Duke of Edinburgh was admitted to hospital with a bladder infection on Monday, causing concern and casting a shadow over celebrations of Queen Elizabeth's Diamond Jubilee.
But the latest Buckingham Palace report says he is on the mend and in "good spirits", although he will remain in hospital for a few more days yet.
After visiting his father on Tuesday, Prince Edward said the duke was feeling "much better," adding he was "in good spirits, he's on good form".
He said that Philip had watched the thanksgiving service at St Paul's cathedral on television.
"He's feeling a lot better, he just needs some rest."
Speaking of his mother, Edward said the monarch was "bearing up," adding: "She's missing him, obviously."
Edward's wife, Sophie, said the duke was "naturally upset" to miss out on the end of the Jubilee celebrations, but added: "He's on good form. He is in good spirits."