They threw a quiet little farewell party for Ernest W. Lefever last week in the State Department's bureau of human rights. When the party was over, Lefever left the building for a last time, his government career as an assistant secretary of state-designate for human rights officially at an end.

But Lefever's decision to withdraw his name from consideration after his nomination was rejected decisively by the Senate Foreign Relations Committee did not mean the end of the matter for the people he left behind in the bureau's seventh-floor offices.

For the 30-some employes of the bureau, the end of the controversy over Lefever is likely to mean weeks or months of uncertainty about the bureau's status in the Reagan administration.

The uncertainty of the moment was summarized last week by Stephen E. Palmer Jr., a career foreign service officer who has headed the bureau in an acting capacity since Jan. 20 while Lefever awaited Senate confirmation. Declining to be interviewed on the bureau's future, Palmer sent word through an aid that "all I could say is that we don't know. Everything is up in the air."

So it would seem. On Capitol Hill, Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) has suggested this may be the time to abolish the job and disperse the bureau's functions throughout the State Department.

White House chief of staff James A. Baker III said in a television interview that he had "noted with interest" the majoirity leader's suggestion. At the least, Baker said on the June 7 broadcast of "Face the Nation" (CBS, WDVM), President Reagan is likely to take some time before nominating anyone else for the assistant secretary's post.

But on the other side of the argument, opponents of the Lefever nomination such as Sen. Paul Tsongas (D-Mass.) are calling for the post to be filled quickly and suggesting conservatives they would find acceptable.

In the midst of this pulling and tugging, the human rights bureau has continued to function, performing a number of duties mandated by law, such as reviewing the human rights records of governments that seek U.S. military or economic aid. The protracted fight over the Lefever nomin U.S. military or economic aid. The protracted fight over the Lefever nomination and the prospect that it may be months before a new nomination is sent to the Senate, if one is sent at all, has not affected morale in the bureau, according to State Department, officials.

But there is also a recognition that what the administration finally decides to do about the vacant assistant secretary post will have a substantive as well as a bureaucratic impact.

A decision to leave the job vacant, one official noted, "eventually will make a difference in that we won't be able to fight as well. If other bureaus have someone appointed by the president, and we don't, we don't have as much clout" in the department policy fights.

The fact that there is such a job in the State Department, established by law, is an outgrowth of the Carter administration's policy of emphasizing human rights as a key ingredient of U.S. foreign policy. In 1976, Congress enacted legislation creating the job of coordinator for human rights, the first time a specific post dealing with human rights issues had existed in the State Department.

A year later, in the early months of the Carter administration, the job was elevated to the assistant secretary level and the bureau was created. Beginning with only a handful of employes under Patt Derian, the first and only assistant secretary to head it, the bureau grew during the Carter years to its present size of 32 jobs.

Human rights was an issue between Reagan and former president Carter during the 1980 campaign, as Reagan accused his predecessor of ignoring vital U.S. interests while pursuing naively idealistic human rights goals.

His policy, the new president suggested, would be more balanced, with emphasis on human rights violations in the Soviet Union and other communist countries and the use of "quiet diplomacy" when dealing with human rights abuses in noncommunist countries friendly to the United States.

The nomination of Lefever, an outspoken critic of the Carter approach, was meant to symbolize the change in approach.

But with the Lefever nomination withdrawn, the administration must once again decide what it wants to do with the human rights job and, by implication, the whole human rights apparatus in the State Department.

In the aftermath of the Lefever setback, the administration is being urged by, among others, Sen. Jesse Helms (R-N.C.), to consider doing away with it all.

John Carbaugh, an aide to Helms, said the North Carolina conservative is committed to human rights but has concluded human righst should be a concern throughout the State Department and not be concentrated in a special bureau. "We need an assistant secretary for human rights as much as we need an assistant secretary for motherhood," he said.

But Tsongas said to abolish the post would amount to "a public disavowal of our human rights policy" that would be "the kind of thing the Soviet Union would have to applaud."

Instead, Tsongas said, the White House should consider nominating someone like columnist Michael Novak or prominent New York Republican lawyer Rita Hauser for the post. Either of those nominations, Tsongas predicted, would "fly through" the Senate.

White House officials seem in no hurry to follow Tsongas' advice. Baker, the White House chief of staff, said he did not know the president's attitude abour abolishing the human rights job but did think Reagan "will move very slowly in coming up with any other nominees."

Just how slowly the president does move may answer the question of whether, having been denied his first choice, he thinks the job should be filled at all.