Ivar H. Peterson, 68, a member of the National Labor Relations Board from 1952 to 1956 and an adminstrative law judge with the NLRB from 1962 until he retired last January, died of cancer Monday at the Washington Home Hospice.

Mr. Peterson first began working for the NLRB in 1938 as a review attorney. He later served with the Board's trial examiners division and as an assistant general counsel before leaving in 1946.

He spent two years with the National Association of Broadcasters in Washington and was adminstrative assistant to Sen. Wayne L. Morse of Oregon from 1948 until being named a board member in 1952.

After leaving the board a second time, he practiced law in Seattle, was a union official, and taught law at the University of Cincinnati before returning to Washington.

He was a member of St. John's Episcopal Church in Georgetown.

Mr. Peterson was born in Finland and reared in the state of Washington. He graduated with highest honors from the University of Washington in 1929 with a bachelor's degree in political science. He was a 1933 graduate of Duke University's law school.

He and his wife, Elizabeth, who survives him, made their home in Arlington.