0944 GMT July 21, 2018
The book, which measures 1.6 inches by 2.4 inches, is to be auctioned by Bloomsbury of London this month, standard.co.uk reported.
Just 31 pages long, the unique manuscript was created by the author for charity in 2004.
It contains short extracts and sketches associated with her first novel, Harry Potter and the Philosopher’s Stone.
It features hand-drawn images by Rowling of a cauldron, a wand and a witch’s hat, and a lists of books Harry needed for Hogwarts.
The manuscript ends with the words “From Harry Potter and the Philosopher’s Stone, by me”.
Despite being 13-years-old, the hardback miniature is in perfect condition, written in black ink with a green and gold cover.
Its current owner, a private collector, bought it for about £10,000 in 2004. But now it will go to auction at Bloomsbury of London, where it is estimated to sell for between £80,000 and £120,000.
The sale comes as the first Harry Potter book reaches its 20th anniversary.
Clive Moss, of Bloomsbury, said: "This is the first complete book of its type and is incredibly rare and unique.
"It dates back to 2004, when there had only been three Harry Potter movies released. This pre-dates much of the Harry Potter lunacy that was to come.”
Several first edition copies of the book have sold for huge sums already this year, with a hand-signed edition sold for a world record £106,000 last month.
Moss added: "At the moment with the 20th anniversary, Philosopher's Stone items are sky-rocketing in price and we're really hoping to get some good interest in this over the next few weeks.
"We've set a guide price of between £80,000 and £120,000 but no one knows where the current crazy prices are going to end, so who knows what it could make.”
The sale takes place on December 14.