While a thousand policemen combed France today looking for Albert Spaggiari, underworld chums of the organizer of the $10 million "sewer rat" burglary of a Nice bank last summer were icing champagne to drink as soon as they hear that he is safe.

For the police, the main item on the menu was the egg on the face of the guards who let Spaggiari escape from a Nice courthouse yesterday. French press accounts of the escape expressed admiration and even glee over the ex-paratrooper's skill and daring in outwitting the police again.

Interior Minister Michel Poniatowski ordered an investigation of the police guard that Spaggiari escaped by jumping from a second-floor window at the courthouse, landing on the roof of a parked car 20 feet below and then being whisked away by an accomplice waiting on a motorcycle more powerful than those of the police.

Police speculated today that Spaggiari may have gone straight from the courthouse to the Nice airport and caught a flight to Zurich 15 minutes after his escape.Police neglected to notify the airport until after the flight had left.

There was no confirmation of this theory but detailed planning is Spaggiari's trademark.

He and a dozen accomplices tunneled through a sewer wall into a Nice bank vault over a weekend last July. They set up picnic tables for meals and air mattresses for sleeping as they leisurely rummaged through safe deposit boxes. On leaving, Spaggiari scrawled on the vault's wall, "without arms, violence or hate."

Arrested last October, Spaggiari immediately confessed and told with gusto how he planned and executed the burglary. His memory became hazy only on what happened to the loot, little of which has been recovered.

Jacques Peyrat, his lawyer, has said that Spaggiari's share went on to an underground rightist organization based in Italy. Spaggiari served with the French colonial forces in Indochina and Algeria, and worked as a photographer in Nice.

Peyrat was as stunned by the escape as were the police guards who left the accused thief, the lawyer and the investigating magistrate alone late yesterday afternoon in the same office where the three had been meeting at the same for the past 10 weeks.

"No, not that!" the lawyer shouted as he saw Spaggiari stand up and move toward the the window, thinking that his client was about to attempt suicide.

"The lawyer obviously didn't know his man," the usually somber Paris daily Le Monde reported ironically under the headline, "The Fantastic Escape." While Le Monde called his escape another example of "the brain drain" from France's institutions, the leftist Liberation felt compelled to remind its readers that "unfortunately Spaggiari is a notorious fascist."

The French Communist Party daily L'Humanite hinted darly that the government had helped him escape, because "some people seem to be less dangerous free than in prison."

In a small bar in Nice that was a hangout for "bert," as Spaggiari is called by the band of rightist underworld figures who had sworn to help free him, his friends told reporters that they had put seven bottles of champagne on ice for luck and uncorking as soon as they got word that he had reached a safe destination.

Missing from the party will be Spaggiari's wife. Without being noticed by the police, she disappeared two weeks ago. "She was tired and went away on vacation," a friend told reporters today.