At age 98, she’s still a “Red Menace!”

A Manhattan federal judge Thursday shot a down a bid by a retired 98-year-old New Jersey teacher to overturn her 1950 McCarthy-era conviction in an atomic espionage case considered a run-up to the spy trial of Julius and Ethel Rosenberg, saying there’s no proof the elderly woman was denied a fair trial.

Miriam Moskowitz had previously told The Post she wanted to clear her name before she died, but Thursday, she said she wouldn’t be appealing the latest ruling.

“That’s it,” she said with her head down. “I can’t do anything more.”

Judge Alvin Hellerstein said the nearly 60-year-old grand-jury records unsealed in 2008 that Moskowitz was relying on to clear her name didn’t prove that the only witness who testified against her at trial told the FBI a different story that could have helped her defense.

“The error, if any, is not fundamental,” Hellerstein said. “There is nothing showing it would change the results.”

Moskowitz and her lawyers claimed the transcripts proved she was unaware of a conspiracy to lie — and that her alleged accomplice, Harry Gold, fingered her at trial only after being threatened with the death penalty for other espionage crimes. If her lawyers in 1950 knew of Gold’s earlier statements, they could have cross-examined him, Moskowitz argued.

The judge said Moskowitz’s lawyers in 1950 should have legally pursued access to review the sealed records – even though they likely didn’t know the records existed. He also said Moskowitz shouldn’t have waited six years after the records were unsealed to make her case.

Walking with a cane, the frail but feisty Moskowitz told reporters that she believes Hellerstein interpreted the facts wrong.

When asked how she felt, she said, “Too bad. My 98-year-old life goes on. It’s not affecting me one way or another — except that I am disappointed because it reflects really not so much on me but on the prejudice of the McCarthy era.”

When asked why she waited six years to appeal the case, she said she didn’t have enough money until recently to hire a lawyer.

Moskowitz spent two years in federal prison and was hit with a $10,000 fine after being convicted by a jury in 1950 — along with her married lover, chemical engineer Abe Brothman and one of his associates, Gold — of lying to a grand jury.

Brothman had been accused of passing secret industrial information to a woman named Elizabeth Bentley, who then sent it on to the Soviet Union. Gold was charged with replacing Bentley.

Gold threw Moskowitz under the bus at the trial by testifying that she knew he and Brothman were plotting to lie to the panel.

Government lawyer Roy Cohn, who gained infamy during the McCarthy hearings, helped prosecute her. He called the case a “dry run” for the notorious Rosenberg trial.

Brothman and Gold both died after serving prison terms.