ELLEN DeGENERES is using a tell-all memoir to get the last laugh in her infamous split with ANNE HECHE.

The Emmy-winning comic recently inked a publishing deal for a new book, and insiders say the gloves are coming off!

"Ellen’s always taken the high road when it came to divulging secrets about her years with Anne," a publishing insider told The ENQUIRER.

"But now she’s ready to spill all the details."

The 52-year-old talk-show queen had a three-year romance with Anne, 41, in the late ’90s

 A few days after their split, Anne had a bizarre meltdown after taking the drug Ecstasy. She was found wandering outside Fresno, Calif., half-naked and shouting strange phrases and obscenities.

"When they split, Ellen bit her tongue," the source said.

"But she’s finally prepared to tell the world how Anne used her as a Hollywood stepping stone.

"She’s got no problems now talking about Anne’s bizarre behavior, her drug use, and the way she used men to make Ellen jealous.

"Ellen is using this book to settle an old score."

For ALL the details pick up the new ENQUIRER – on sale now!