French auction house Osenat confirmed reports today that the palace's museum would hold the auction on November 15 and 16 in Fontainebleu, near Paris.
The collection, consisting of nearly 1,000 items including manuscripts, weapons and paintings, was mostly put together in the early 20th century by prince Louis II of Monaco.
A black felt cocked hat, which was worn by the emperor during his imprisonment on the island of Elba, is valued at between 300,000 and 400,000 euros (USD 410,000 to USD 545,000).
Experts told AFP it will be the "sale of the century" for buyers interested in the period, but not everyone is pleased.
"I regret that the contents of the museum are being dispersed," said Jean Etevenaux, head of the "Remembering Napoleon" society, which brings together connoisseurs on the era.