At least three members of the U.S. embassy staff disregarded Ambassador Malcolm Toon's order to evacuate the burning building during last weekend's fire and remained inside to see that no Soviet firemen got inside the super-secret 10th-floor offices of the military attaches.

One of them said. "It wasn't that we disregarded or disobeyed. It's just that we were a little slow responding." He said it took the men two hours to respond to Toon's order and by that time the fear that the building would collapse from the effects of fire and water had passed.

Toon had ordered the Americans out after a Soviet fire official warned him the building might collapse. Saturday the ambassador said that for perhaps 20 minutes no American was in the building while Soviet firemen were alone in sensitive offices.

The men who stayed behind periodically checked the heavy metal door securing the 10th-floor offices and several time left their ninth-floor posts to don air tanks unlock the military attaches' main entrance to peer into the heavy smoke inside for any Soviets. After the fire was over, aides found that a metal door to the roof, where firemen fought flames, unaccompanied by American personnel had remained locked.

Other embassy sources said four Soviet firemen accompanied by Americans were inside the sensitive records section on the ninth floor, where file cabinets filled with thousands of cable messages stood open. But a check of these files has shown that nothing is missing, a source said today. One of the American monitors was posted with a camera inside the room to record any attempt to take materials, a source added.

It was learned today that the handles of several locked safes in the scientific section of the fire-ravaged eighth floor were knocked off, but the safes remained locked. No explanation was offered for how it could have occured, but one American commented, "If I were in a Russian embassy under the same circumstances, I might try the same thing."

The man on duty in the embassy's secret communications room on the ninth floor was able to lock all safes and the main door inside, sealing the stoutly built space as though it were a large safe. One source said it took several persons an hour to reopen the complex, electrically timed lock.

Meanwhile, Toon was scheduled to meet Thursday with the embassy staff to discuss the fire and its aftermath. One of the topics will be a demand by some staffers that the extra pay for State Department employees stationed in Moscow be raised to 25 per cent above base salary from the present 20 per cent. These staff members reportedly contend that the fire proves that the embassy is a far more dangerous place to work than previously allowed for.

Other employees are known to be angry that the building's main alarm did not sound during the fire and that residents were roused by teams pounding on the doors t their apartments. They said that the door-pounding could have gone unheard by sleeping occupants.