With an increasing number of Americans leaving religion behind, the University of Miami received a donation in late April from a wealthy atheist to endow what it says is the nation’s first academic chair “for the study of atheism, humanism and secular ethics.”

The chair has been established after years of discussion with a $2.2 million donation from Louis J. Appignani, a retired businessman and former president and chairman of the modeling school Barbizon International, who has given grants to many humanist and secular causes — though this is his largest so far. The university, which has not yet publicly announced the new chair, will appoint a committee of faculty members to conduct a search for a scholar to fill the position.

“I’m trying to eliminate discrimination against atheists,” said Mr. Appignani, who is 83 and lives in Florida. “So this is a step in that direction, to make atheism legitimate.”

Religion departments and professors of religious studies are a standard feature at most colleges and universities, many originally founded by ministers and churches. The study of atheism and secularism is only now starting to emerge as an accepted academic field, scholars say, with its own journal, conferences, course offerings and, now, an endowed chair.