A number of economists breathed a sigh of relief yesterday when the White House named Treasury Undersecretary for Monetary Affairs Beryl Sprinkel as chairman of the president's Council of Economic Advisers. They had been afraid that the president would seek instead to abolish the council.

"I am delighted that the president is keeping the CEA," declared Murray L. Weidenbaum of Washington University, who was Reagan's first CEA chairman. "That is good news." He added that he was also delighted that the choice was Sprinkel.

Another former CEA chairman, Alan Greenspan, who served under President Ford and is an outside adviser to Reagan, termed the choice "an obvious appointment in conjunction with former Treasury Secretary Donald T. Regan going to the White House as chief of staff . It is important that the CEA chairman be someone whom Regan feels comfortable with.

"Beryl has been around quite a while, and he is familiar with the ins and outs of economic policy-making. I would be hard pressed to find someone who would fit in with the Reagan administration and who will do as good a job as Beryl will," Greenspan said.

But some other economists, who spoke on the condition that they not be identified, expressed satisfaction with Sprinkel's appointment only in the sense that he is, as one put it, the most able person willing to take the job that the administration would be willing to appoint.

"The first choices we would make would either not be available or would be vetoed by the White House," said one conservative economist only willing to speak anonymously.

"From the profession's point of view, Sprinkel's job there is to rebuild the institution, operate it in a day-to-day basis. The role of the chairman now is to weather the storm," the economist said.

The White House explanation of the appointment seemed to indicate that except for its statutory existence and the difficulty of getting Congress to agree, the president really would have preferred to get rid of the CEA. It also implied that Sprinkel's role will not be that of a close adviser to the president.

There was no indication of candidates for other two positions on the council. Given the stormy relationship between the CEA and Reagan, Weidenbaum was asked, shouldn't any potential member be skeptical about what role he or she could play in the administration?

"Should they be skeptical?" he replied. "The short answer is yes. On the other hand, coming in at a low point, they have nowhere to go but up. It is a challenge." He acknowledged that the circumstances "will narrow the field" of candidates.

At various times, Reagan was angered by Weidenbaum and Martin S. Feldstein, his second chairman, when they questioned whether his policies, particularly regarding budget and tax matters, would produce the desired results. Weidenbaum largely kept his challenge in-house, while Feldstein was far more public with his.

Sprinkel has been criticized in the past for having a very narrow and rigid interpretation of the way in which changes in the money supply affect changes in current-dollar gross national product and inflation. But noted one economist, "Beryl is not as one-sided as he was.

"The real problem that you have got," the economist continued, "is that the other possibilities are not nearly as good as Beryl. I was pleased by it because I was afraid we would get someone a lot worse. With him, it keeps the CEA in operation with some degree of academic validity. Beryl is not a far out appointment."

Walter Heller of the University of Minnesota, a liberal economist who was CEA chairman in the Kennedy administration, noted that the CEA report that was written by William A. Niskanen Jr. and William Poole was "already a monetarist document," so that Sprinkel's appointment would make little difference in that regard.

The report, in chapters written by Poole and Niskanen, said that it is monetary policy that is responsible for determining the rate of growth of current-dollar GNP. Fiscal policy -- tax and spending policies -- only affect the structure of the economy, not its overall size or the rate of inflation, the report argued.

Poole left the CEA last month to return to Brown University. Niskanen, the lone remaining member, intends to resign shortly because he was not named chairman. As late as Tuesday night, he had had no word whether the White House intended to appoint him.