Every weekday morning, a distinguished-looking man in a conservative suit and tie leaves his Northwest Washington apartment and drives his blue Oldsmobile 98 through the morning rush hour to his office three blocks from the White House.

Although secrecy is an important part of the man's business, there is much that the FBI can tell you about him. Arriving at the office by 8:30 a.m., he seldom leaves before 10 at night and often checks in on weekends and holidays to review the stacks of paper that accumulate on his desk. He shuns night life and social activity, and keeps a small circle of trusted friends.

The reason for the FBI's interest in Stanislav A. Androssov is simple: He is a Soviet spy.

According to the FBI, Androssov, 53, is resident chief of the Soviet Committee for State Security, or KGB, directing the covert and not-so-covert intelligence-gathering activities of scores of agents in the United States. Since arriving here last year, he has become a central figure in the Soviet Union's attempt to obtain political, military and technological secrets from the U.S. Asked about his activities as he entered the Soviet Embassy on 16th Street last week, Androssov responded politely, "It is not in the interest of improving our relations to speak about those things," and produced a business card that described his position as a counselor at the embassy. He referred to himself and his colleagues as "we diplomats," and said that in more than 30 years in the diplomatic service "this is the first time I'm getting so much attention from the FBI. I don't understand it."

In recent months allegations of increased Soviet intelligence activity have provoked controversy and chilled East-West relations from Tokyo to Paris to Bonn. Since Jan. 1, according to U.S. authorities, 93 Soviets have been expelled from 13 countries on charges of espionage or interfering in domestic political affairs.

But in Washington, Soviet spying activity--and the American response to it--follows a familiar pattern developed over nearly four decades of Cold War. With the predictability of two long-time dance partners, the KGB and FBI, the agency charged with counterintelligence, are engaged in a kind of stylized pas de deux, acknowledging each other warily in public while carrying on an intense struggle that remains shrouded in secrecy.

Given this secrecy and the sensitive political nature of the issue, assessing damage caused by Soviet espionage is a difficult task. Interviews with FBI officials, intelligence experts and scholars suggest, however, that despite worsening relations between the two superpowers and the accession of former KGB chief Yuri Andropov as Soviet leader, the danger posed by spying has not changed dramatically in the last couple of years.

"The number of Soviet spies remains fairly constant," says Theodore M. Gardner, head of the FBI's Washington field office, adding that there was an increase in activity around President Reagan's inauguration that was natural with the coming of a new administration.

Still, U.S. officials express concern that in the last decade the KGB's operations in this country have become more effective.

"Soviet collection has continued to increase, particularly in the last several years and particularly in areas of scientific and technological collection," said James E. Nolan, former deputy assistant director of the FBI during the 1970s. "They are more organized, more sophisticated, less opportunisitic. There are specific things they are after. I would suggest to you that the Soviets' requirement list would be the size of a Washington telephone directory."

There are about 280 Soviets assigned to their diplomatic mission here, ranging from Ambassador Anatoliy Dobrynin to cooks and drivers, according to U.S. authorities. By FBI estimates, about 130 of those are known KGB intelligence agents or members of the Soviet military intelligence service, the GRU. Nationwide, the FBI says, roughly 35 percent of the 1,300 Soviet personnel stationed in the United States are spies of some kind.

This is a number that has steadily grown over the last decade and been augmented by spies from Communist Bloc countries like Cuba, Poland, Bulgaria and Czechoslovakia. As a result, the FBI has had to change its tactics depending more on electronic eavesdropping.

"It's not possible to do anything like a comprehensive physical surveillance with 1,000 Soviets in the U.S. and a couple of thousand other bloc agents, Nolan said. "Nobody can surveil 3,000 people every day.

"Surveillance has to be selective. It is very different from what it was in the 50s and 60s when the idea was that if you walked around with them they could not do anything. In the 1950s there were about 50 Soviets at the United Nations Secretariat today there are over 300 . Also gone is our ability to know and recognize people."

The FBI's success in thwarting Soviet efforts is hard to measure. In April two Soviets, a lieutenent colonel assigned to the office of the military attache and a diplomat assigned to the nation's mission to the United Nations, were expelled and a third left hurriedly after they were caught in unrelated espionage activities.

But some intelligence experts, like Harry Rositzke, a former CIA official and author of a recent book on the KGB, believe that "we haven't had a good catch here in the last 10 years. How active they are is hard even for the security agencies to assess."

Concern over Soviet successes in obtaining sensitive technological information, partly stimulated by two congressional hearings last year on Soviet spy activity in the U.S., has prompted a newly coordinated effort by the intelligence units of the Pentagon, CIA and State Department to restrict Soviet access to seminars and colloquiums in which scientific and military information is discussed.

"The current effort is pervasive, highly organized, dynamic and well targeted. The effort is directed from the highest levels in the Soviet government. . . . There is no question that the overall loss of U.S. technologies from all sources to the Soviet Union has been extensive," concluded a report by the National Academy of Sciences last year.

In addition, a bill sponsored by Sen. John P. East (R-N.C.) would require citizens of all Communist Bloc countries to register with the Justice Department before attending any hearings on Capitol Hill or contacting any member or employe of Congress.

Although authorities say KGB and GRU officers have made random attempts to find technological secrets from local defense and aerospace industries, most Soviet high-technology espionage goes on in areas such as California's 'Silicon Valley' and Boston's Rte. 128, where high-tech firms flourish. In Washington, political and military information is the objective and in obtaining it the Soviets have an advantage in the openness of American society and the relative availability of information in government and scholarly publications and the media.

Sometimes this openness can be confusing to the Soviets, according to William A. Branigan, an FBI counterintelligence chief in the 1970s. KGB officers here primarily "want to develop sources," says Branigan. "So much in this country is open. But if they can get it clandestinely it's much better; it's 'proof' that they're not being duped. . . . Their country is so different from ours and so controlled, they sometimes have difficulty believing what they hear."

To keep track of Soviet spies in Washington, U.S. counterintelligence officials start from the premise, as one put it, "that everyone assigned to the embassy is KGB or KGB-trained, especially if they are allowed to go out on their own." FBI surveillants are trained to look for KGB officers posing under various guises, such as journalists, trade representatives and political officers at the embassy.

The FBI acknowledges that many of the Soviets' efforts to gather information are traditional activities of any diplomat. But FBI officials are concerned that the open atmosphere of Capitol Hill, in particular, makes illegal espionage easier. Their concern rises at this time of year when summer interns come to Washington and are sometimes given clearance to read security-related documents.

"What these people do, they'll use these legitimate activities of observation, to take mental notes on the personality traits of people," says the FBI's Gardner. "What that officer does, what he's searching for--that weak link, that breach of security which could allow them access to certain materials or a personality in office who could be worked on."

Still, some think the KGB contacts on the Hill are not as dangerous as the FBI makes out. "I think the FBI exaggerates their the KGB's nefarious activities on the Hill; they don't go up there and chat with someone and don't assume they're not being followed," said Rositzke, who also calls East's proposal for the registration of Soviets "kind of silly."

Cliches about KGB spies are not clues to identifying them, according to U.S. intelligence experts, because traditional stereotypes do not fit anymore. No longer the sort who "wears baggy suits and drinks gallons of vodka," as a KGB defector put it, KGB officers are often cosmopolitan, sophisticated, fluent in English and savvy about the American life style.

"The majority of the officers working for the KGB external intelligence are very sophisticated and are well-versed in national psychologies, what is the best approach to the Chinese or Japanese or Americans," says Stansilav Levchenko, a KGB major who defected in 1979. "They have piles and piles of files on the U.S. that each young officer is supposed to study thoroughly before he gets assigned to the U.S. We are not talking about really naive people coming here who have to spend a couple of years to adjust themselves to the U.S."

Androssov, whose expertise is the Far East and China and who was once stationed in Thailand, apparently was an unusual choice for the administrative job of KGB resident chief in Washington. Unlike his predecessor, Dmitri I. Yakushkin, a cultured man with the rank of major general who was the KGB resident for six years in Washington before he returned to Moscow, Androsov did not work in the U.S. before taking up his top post here in April 1982. He had worked here only a few months before taking over from Yakushkin. There is some question about why he was sent without first working for the department that handles U.S. affairs in the KGB's First Directorate.

Androssov, more a bureaucrat than a cloak-and-dagger operative, works out of the embassy on 16th street (a new embassy is under construction on Tunlaw Road in Northwest Washington). Cloistered in an office on the top floor, separated from other embassy personnel, he oversees a staff of dozens of KGB officers whose main job is to gather political intelligence that will help the Soviet Politburo forecast U.S. moves. His wife Valentina works in the consular section of the embassy. And his son Andrei, a former third secretary at the Soviet Embassy in Paris, was among the 47 Soviets expelled by the French in April.

In addition, Androssov has another important function. He monitors a select group of KGB officers--the stukachi, or informants--whose responsibility is internal security: spying on their KGB colleagues, military intelligence officers, Soviet diplomats and other embassy personnel. The KGB oversees all contacts between Soviets and foreigners and can veto any contact viewed as unjustified.

"The diplomats hate and dislike the KGB because the KGB watches them," says Arkadi Shevchenko, a former under secretary general of the United Nations who defected in 1978. "Each embassy has a security officer and he is the most hated person in the embassy. . . . It is a situation of uncertainty. Even Foreign Minister Andrei Gromyko didn't like the KGB. Even his wife. She and my wife were talking in our apartment in New York about shopping, or gossiping, and she stopped my wife and pointed to the ceiling as if to say the KGB is listening. She would not even talk in the car. She made clear she was not afraid of the CIA, but of the KGB."

Apparently some Americans are skeptical enough about Soviet contacts to frustrate KGB officers trying to carry out their duties. "There is a wide campaign in your paper and the media that the Soviet Union tries to obtain some documents," says senior economist Anatoliy Y. Godakov, who works out of the Soviet Trade Office on Connecticut Avenue and is suspected by the FBI of being a KGB officer.

"Probably some persons are not friendly to us as a result of the campaign which is directed against our people, but I think this campaign is groundless."

For the most part, however, the espionage war in Washington is waged with a certain degree of humor--on the surface anyway. In his high-rise office at Buzzard Point, Gardner, 53, the main KGB-watcher in Washington, likes to show visitors a a special piece of memorabilia framed on the wall. It is the shield of the KGB with its motto in Russian: "Shield and Sword of the Revolution."

His chief antagonist, Androssov, meanwhile, praises his temporary home. "I like it here. I like Washington very much," he said last week. "Very hospitable people. You know sometimes it is like a small village, everyone saying hello."