Roger Robb, 78, a retired judge of the U.S. Court of Appeals for the District of Columbia circuit, died of respiratory failure Dec. 19 at his home in Washington.

Judge Robb was nominated to the bench by President Nixon in 1969. He achieved senior judge status in 1982 and retired earlier this year. As a member of what is often described as the most active court of appeals in the nation -- and one which has been widely noted in recent years for its willingness to stake out new protections for criminal defendants -- he held the opinion that the system works best when it is left to competent trial judges and attorneys rather than to appellate courts.

He stated this view in a 1981 case in which he upheld standards set by the Environmental Protection Agency for controlling ozone in the atmosphere.

"The proper function of the court is not to weigh the evidence anew and make technical judgments," he said. "Our role is limited to determining if the administration made a rational judgment."

He held similar views on criminal matters. At his retirement ceremony, Paul L. Friedman, one of his former law clerks, said Judge Robb put his faith in the principles of proving truth beyond a reasonable doubt, the presumption of innocence and due process of law. If these are observed, the judge believed, new procedures are unnecessary.

Often these ideas led Judge Robb to confirm criminal convictions, as it did in 1977 in the first major appellate court discussion of "Sting" tactics used by police here. The appeal was brought by two men who had been convicted of selling a sawed-off shotgun to undercover officers. One of the grounds on which they sought a reversal was the idea that the police had trapped them into criminal activity.

The fact that one of the men had on 18 occasions gone to the warehouse where the undercover officers had set up the "Sting," Judge Robb said, "negates even a colorable contention that the defendant was an innocent person instigated to crime by the police. . . ."

In another case, the question was whether a defendant's rights had been protected adequately in D.C. Superior Court. It came to the federal Court of Appeals because the defendant had asked the U.S. District Court for a writ of habeas corpus on the grounds that his rights had been violated.

All nine members of the appeals court heard the arguments. Eight said the application to the U.S. District Court was permissible. Judge Robb said it was not. His dissenting opinion, which later was adopted by a unanimous Supreme Court, said that it must be presumed that Superior Court judges are just as careful in observing constitutional procedures as are judges of the U.S. District Court.

Apart from sitting as an appellate court, Judge Robb was a member of a panel appointed by Chief Justice Warren E. Burger to name special prosecutors to conduct independent investigations of alleged wrong-doing by high government officials. He appointed the prosecutors in such matters as those involving Hamilton Jordan, President Carter's chief of staff, and two Reagan appointees, Attorney General Edwin Meese III and Labor Secretary Raymond J. Donovan.

In the years before he joined the bench, Judge Robb was an attorney in Washington who handled some cases of very high general and political interest. Among them was his successful defense of Earl Browder, the head of the U.S. Communist Party, against contempt of Congress charges. The future judge was assigned to that case by the U.S. District Court.

Other widely noted clients were Bernard Goldfine, a central figure in the influence peddling scandal that led to the resignation of Sherman Adams as President Eisenhower's chief of staff, and Lewis Strauss, then head of the Atomic Energy Commission, in the proceedings in which Robert Oppenheimer, a father of the atomic bomb, was stripped of his security clearance. The latter was one of the truly controversial episodes of the communist scare of the early and middle 1950s. President Kennedy subsequently restored Oppenheimer's clearance.

Roger Robb was born on July 7, 1907, at Bellows Falls, Vt. His father was Charles Henry Robb, a judge on the U.S. Court of Apeals here from 1906 to 1936. The boy grew up in Washington, graduated from the old Western High School and earned bachelor's and law degrees at Yale University.

He worked in the U.S. attorney's office from 1931 to 1938 and then went into private practice. He was a former chairman of the Legal Aid Society of the District of Columbia.

His firt wife, the former Lillian Nordstrom, died in 1983.

Survivors include his wife, the former Irene Rice, of Washington; one son by his first marriage, Charles Cooper Robb of Pittsburgh; one sister, Priscilla Robb Billings of Falmouth, Mass., and one grandson.