Dr. Robert Breese Shaffer, 76, a retired official of the Central Intelligence Agency and art professor at American University, died of cancer Oct. 30 in his home in Bethesda.

Dr. Shaffer joined the CIA in 1948, where he held various posts in training and administration before retiring in 1968. He also was a member of the agency's fine arts advisory group, historical board, and personnel and career management boards.

He began teaching at American University in 1963 as an adjunct professor in the fine and applied arts cepartment. He was an associate professor from 1969 to 1975, then taught part-time until finally retiring in the spring of 1982. He also had lectured for the Smithsonian Associates on Greek and Roman art.

He was a member of the Archeological Institute of America and the Society of Architecural Historians.

Dr. Shaffer was a native of Lima, Ohio, and earned a bachelor's degree in chemistry at Oberlin College. He received master's and doctoral degrees in art history from Harvard University.

During the 1930s, he was an instructor at Athens College in Greece, and art department chairman at Hollins College in Virginia. He served in the Mediterranean theater with the Navy, attaining the rank of lieutenant commander, and with the Office of Stategic Services during World War II.

Survivors include his wife, Elizabeth, of Bethesda; a son, James, of Gaithersburg; a daughter, Catherine Shaffer of Philadelphia, and a brother, Joe, of St. Petersburg, Fla