Venezuelan Chief Justice Luisa Estella Morales said a manual recount couldn't work in Venezuela because the country's voting system was "completely automated."
Furthermore, she said, there was no legal basis for a ballot-by-ballot audit of the narrow presidential election results.
Maduro beat opposition leader Henrique Capriles by a narrow margin Sunday and will serve out the late Hugo Chavez's term as Venezuela's president.
Capriles had requested a recount.
The comments by Morales contrasted with pronouncements by Maduro and senior officials that a recount could be possible.
Maduro, 50, Chavez's handpicked heir and union activist who became acting president when Chavez died of cancer in March, won with about 7.5 million votes, or 50.66 percent, compared with about 7.3 million votes, or 49.1 percent, for Capriles, the National Electoral Council said.
With more than 99 percent of the votes counted, the percentage separating the two amounted to about 234,000 votes, the council said.
Voter turnout among Venezuela's voting-eligible population was 78.7 percent, below the record 80 percent-plus the election overseer reported in October, when Chavez defeated Capriles 55 percent to 44 percent. Capriles, 40, is a law graduate and former national legislator who is governor of Miranda, Venezuela's second most-populous state.
Capriles said he didn't accept the latest results and called for an immediate recount. Maduro said he would welcome a recount. There was no immediate reaction from either side after the Supreme Court comments.
Sunday's election came less than six weeks after Chavez, 58, died at a Caracas military hospital after a long battle with cancer.
U.S. Secretary of State John Kerry called for a recount of Maduro's narrow win but Maduro told Kerry to mind his business.
"We think there ought to be a recount," Kerry told the House Foreign Affairs Committee on Capitol Hill, but added, "I don't know whether it's going to happen."
Kerry also told the House panel he hadn't determined if Washington would recognize Maduro's victory as legitimate.
"That evaluation has to be made and I haven't made it," he said.
"Obviously, if there are huge irregularities, we are going to have serious questions about the viability of that government," Kerry said.
Maduro responded at a news conference in Caracas that Kerry should steer clear of Venezuelan politics.
"It's obscene the U.S. intervention in the internal affairs of Venezuela," Maduro said at the Miraflores presidential palace.
"Take your eyes off Venezuela, John Kerry. Get out of here. Enough interventionism," he said.
Of the possibility Washington might not recognize his election, Maduro said: "We don't care about your recognition. We have decided to be free and we will be free and independent, with you or without you."
At least eight people have died and 72 have been wounded in protests since the election.
An opposition demonstration in Caracas was canceled Wednesday after Maduro threatened to use "a hard hand" against protesters.
In Washington, White House spokesman Jay Carney urged all sides to avoid violence and other measures "that could raise tensions."
"We call on the Venezuelan government to respect the rights of Venezuelan citizens to peaceful assembly and free speech," Carney said in a statement.