Even US Treasury Secretery Steve Mnuchin is feeling the burn of falling real estate prices.

He has just relisted his apartment at 740 Park Ave. — and slashed the asking price more than 20 percent from when the co-op first went on the market in 2018.

Mnuchin’s sprawling duplex on the eighth and ninth floors hit the market for $32.5 million two years ago; it was last listed for $27.5 million in 2019. It now has a price tag of $25.75 million.

740 Park is one of the city’s poshest addresses, dubbed “the world’s richest building” by Michael Gross, an author of a book on its history.

Mnuchin bought the palatial five-bedroom pad from his aunt, Carol Lederman, around 20 years ago for $10.5 million.

The home comes with a private elevator landing and features high ceilings, a grand layout and multiple woodburning fireplaces.

Famed architect Rosario Candela designed the building, which was developed by Jackie Kennedy Onassis’s grandfather, James Lee.

The listing brokers are Carol Terner Lederman — the former owner of the unit — and her daughter Judy Kloner, both of Warburg Realty. Both brokers declined to comment.