GIZA, Egypt (AP) _ A Franco-Egyptian team of architects and archaeologists deep inside the Great Pyramid of Cheops on Wednesday began boring into a secret chamber undisturbed for more than 4,500 years.

There is no indication as to what they might find upon piercing the 10- foot-thick slab.

The team, using sophisticated drilling equipment loaned by two French companies, hoped by the weekend to slip a tiny camera through a hole 1 1/4 inches in diameter to peek inside the cavity. They bored 22 inches into the slab Wednesday.

Experts say the chamber may hold nothing more than modern, polluted air. But it conceivably could contain treasures beyond imagination, like those that greeted Englishman Howard Carter in 1922 when he entered the burial chamber of the boy Pharaoh Tutankhamen, the famed ''King Tut.''

Ahmed Kadry, head of the Egyptian Antiquities Organization, squatted beside workers perspiring and puffing in the oxygen-scarce passageway.

''Perhaps it will turn out to contain something exciting,'' he said. ''Cheops' pyramid is one of the most fascinating monuments in the world. It is a symbol of what mankind can build, and anything we can learn about it is wonderful.''

Egyptologist Wafaa Taha el-Siddiq of the Antiquities Organization quipped as the drill began to whine: ''You know there are some people who say this is the magic stone that holds the whole thing up.'' Then she said, ''I hope not.''

The pyramid, one of the seven wonders of the ancient world, was built near two others over a 70-year span in the 27th century B.C. The largest of the three monumental pharaonic tombs, the Cheops pyramid comprises 2.5 million limestone blocks and is 482 feet tall. Its base covers 13 acres.

French architects Gilles Dormion and Jean-Patrice Goidin discovered anomalies in the pyramid's structure last winter while probing its passageways with a microgravimeter, a sonar-like device.

Perplexed, they returned to France, read all they could find on the pyramids and decided to pursue their investigation. They made their case to the French Foreign Ministry and received government funding for the project.

Denis Louche, French cultural attache in Cairo and amateur archaeologist, contacted the Electricite de France, the state electricity company, about helping.

The company had just announced the discovery of l'Orient, a research ship that sank with scientific material for a Napoleonic expedition in Egypt.

''Louche told us only that some cavities had been found somewhere and asked if the same equipment used to locate (the ship) could be used inside structures,'' said company official Jacques Montlucon, on hand in Cairo for the drilling.

''We found the same anomalies (that the architects had found), and so we were able to convince Egyptian experts that a survey might be in order,'' he said.

Such cavities had been discovered in the neighboring pyramids of Chephren and Mycerinus but never before in Cheops'.

Another French firm, Compagnie Prospection Geophysique Francaise, is providing expertise and equipment for the drilling.

Scientists selected the largest of the cavities in the belief that it was a more likely repository of artifacts than the others.

''I think we found these cavities because we are architects, and we look at things differently. We weren't looking for mystical experience. We were looking for construction details,'' said Goidin on Wednesday.

''Why did he (the pyramid's designer) make such a passage with the floor laid after the wall? Perhaps to hide secrets.''