Gertrude Skinner Finzel, 75, a secretary and administration assistant in the federal government for 40 years before her retirement in 1972, died of cancer Tuesday at Sibley Memorial Hospital.

A third-generation Washingtonian, she was a graduate of Business High School and attended George Washington University and the Washington School of Secretaries.

Mrs. Finzel began her government career with the Reconstruction Finance Corporation as a secretary to one of its officials, Rene J. Taylor. When he was sent to Manila in 1948 as chairman of the board of review of the Philippines War Damage Commission, she went as his administrative assitant.

Returning to Washington in 1950, Mrs. Finzel became secretary to the assitant director of the Office of Price Stabilization, and then an organization and methods examiner there.

She worked at the Pentagon briefly before becoming secretary in 1954 to Carlton G. Beall, U.S. marshal for Washington. She continued in that position when he was succeeded in 1958 by James P. McShane.

Mrs. Finzel also worked for him when he became head of all U.S. marshals in this country. After his death in 1968, she returned to the office of the U.S. marshal for Washington, where she remained until retirement.

She was a member of St. Anthony's Catholic Church in Washington.

She is survived by her husband, Felix E., and a brother, John P., both of the home in Hyattsville.